Dont try linux mint, for obvious reasons. Mint is for someone who uses computer to browse web and thats about it.. For grandparents.. Packages/apps are outdated, and sometimes buggy and then youre stuck with buggy system.
I suggest you use archlinux.
CachyOS while its archbased, they, have done great work, but.. from what i experienced, they limited one packaged (not instaleld out of the box for some reason) that does not allow for you to set up KDE Discover app that is like app store for flatpaks (flatpaks are containerized apps that are like docker or soemthing but not exactly) apps with limited permissions (safer).
If you are confident with terminal and dont mind installing and managing flatpaks (apps from here https://flathub.org/en) then go with cachy, as they custom tailor the system to "work" as performant as possible
But if you want to learn how linux work and grow your linux beard and knowledge then dive into arch. Arch will teach you how to read manuals - wiki and how to break system and fix it. How to do and how not to do.
As for any other, imo those companies behind them - RHEL FEDORA UBUNTU etc etc are for people like grandparents who use the computer on surface level and dont mind using outdated apps.
Arch has the most up to date apps as they come. Cachy has access to the same packages as arch.
As for desktop environments i suggest KDE Plasma Wayland. Wayland is the most popular most up to date compositor? idk or protocol. The other one is x11. Wayland allows you tu run different monitors at different scaling resolution and refersh rate, no problem like on windows. x11 has issues. And most desktop environments are dropping support for it.
Before you nuke your windows, install virtualbox (free) download linux iso (free) and try to install it there. Give 50gb storage (usually enough). Thats how i did my switch from windows. I learned how to install apps and how to set things up that i needed.
For arch, once you boot the install, just type archinstall and follow the prompts from top to down. And youll be able to set things up.
I suggest you use btrfs (file system) as this is the one that lets you take snapshots. If you go with cachyOS and use btrfs they set it up for you with automatic snapshot system, so when you upgrade or install one or many apps, it create snapshot before of the whole system (not sure if user data aswell, maybe not with user data), and then adds that snapshot to the boot menu so in case you one day after upgrade break somehting you can reboot into that snapshot before your upgrade.
As i set up my system without that (cuz i didnt know how all worked) now i regret cuz i have made few upgrades that broke my gpu drivers. And am waiting for them devs to fix it. With this it would be one reboot and youre on your previous system.
BTRFS stores data deltas as i understand it so its not like if your system is 50gb and you take snapshot then it becomes 100GB of storage use. And you can manage the snapshots with GUI apps etc. etc.. real easy on cachyOS..
You can (and i will) set this system on arch as well.. I have tested this in VM and was succesfull.. Took me 1h after a clean arch install. you just need to know what to select in archinstall menus to set this up properly.
Other than that, most of the apps you mentioned are in the arch repository, just search for it. To install official apps form here you use 'pacman' in terminal.
https://archlinux.org/packages/
If they are not there, then search user repository - where users make config/packages isntructions to install the package from official source and it compiles on your system, and or its already precompiled binaries. But this is not secure, thee have been bad actors on there, so keep that in mind. You can read the install "script" before installing the app from AUR, and inspect if it does something shady. Usually its just - got clone app/from/source and then make (compile it locally). Ofc depends on the app. To access AUR packages you need to install 'yay' or 'paru'
https://aur.archlinux.org/packages
And then there are flatpaks, that come with their own dependencies and stuff. There are official apps and then user apps on the hub so be advised, that sometimes bad actors live there too. To access this, well if youre on arch, and you have installed KDE and whole KDE stack (remember that archinstall will install basic, not all packages) then youll be able to access the flathub from discover app. And you can also install them from terminal etc etc..
https://flathub.org/en
What else.. just read through arch wiki and try out in VM.. fail a few times and youll get it eventually.
Tomcat
Vector and raster graphics
GIMP KRITA for raster, hmm vector? INKSCAPE maybe never had need for vector graphics.
Video editor and screen capture (export to .gif)
If you use KDE desktop environment, it comes with Spectacle app for screenshots and you can record videos and add arrows to the screenshot and text like windows app ShareX. Other than that OBS kinda works (i dont use it) but many do - for screen capture. As for video editor, i tried davinciresolve, it booted but on Wayland - not x11, it cant work as a floating window, it defaults to fullscreen on a monitor that is active. Kinda a bummer for me, but i dont have a need to cut videos. If i do i use ffmpeg in terminal to trim video or cut a portion. KDEnlive https://kdenlive.org/ i havent tried but im sure it works.. All KDE apps should work on KDE desktop environment.
Editor - audacity, tenacity. FL studio like - LMMs. Not sure what else. Some paid audio DAW have linux support (german one i forgot the name of it).
Browser with VPN (and downloader)
What do you mean downloader? Firefox and Chrome And any other browser are working as per usual. Just install it and it should work. I havent had problems. I use zenbrowser (fork of firefox, i kinda stay away from firefox as they astarted to sell your data to AI corpos).
qbittorrent is and will be the best way to download linux isos using torrent.
Never used VPN so im not sure how it works.. some are like browserr extension, some are system level, so youll have to look that up yourself. As for VPN to a home network like if youre at bahamas and want to access your "linux isos" at home NAS, you can set up wireguard or if youre affrad of terminal then tailscale.
Tomcat Must be able to place videos on the desktop!
What do you mean by this?
Tomcat GPU:
PNY Quadro RTX 5000 16GB
You need to check and consult wiki, ad this is nvidia. Sometimes they change driver packaging and separate (happened recently in past few months) drivers for groups of generations of GPU's. So make sure you install correct driver package. Its not automatically detectd on any linusx system. While it will work when you boot lets say cachyOS, they use general or sometimes open source drivers that usually work on all hardware, but when you will want to use GPU like for games and such, you will need the new features that are not in the default drivers and so it will fail to work. Archwiki has multiple section desribing what GPU series use what drivers (package to install). CachyOS does not explain this in their wiki.
Upon installing steam it will prompt you what vulkan drivers you want - so this will be the time for you to learn what gpu you have and what driver you need.
Tomcat Is it even possible to run a monitor control program under Linux if it is designed for Win?
What do you mean by that.. No proprietary RBG, MSI afterburner, or any other bloat that companies make for windows is on linux. So forget about controlling them.. AS for RGB, some hardware is supported by the RGB controller app (forgot the name) but consult the wiki, what is or is not supported (hardware wise)
Not sure about these, and how they are compiled - linux or windows exe.
As for windows apps on linux, using wine, i suggest use bottles https://flathub.org/en/apps/com.usebottles.bottles Its an GUI app that you can set up to run windows apps with many "DLLs" that some windows apps need, very versatile. Not perfect, but for simple apps it works. Can even play games. I played through Oblivion remasterd on this one that i legally "found" online, amongst linux isos. You can even add to it Steams proton compatibility layers as they come out. and or download glorious egg rolls proton versions to see if the app you want to run works on those.
Also use https://flathub.org/en/apps/com.github.tchx84.Flatseal to manage permissions to folders and such. YOu can also turn off network access for flatpak apps in here, so that ET does not phone home if you know what i mean.
And this GUI app to manage your proton versions https://flathub.org/en/apps/net.davidotek.pupgui2
With my limited experience if you have any question how to do and not do on arch just ask, if i can ill try to help.