T launcher working fine under linux since it java just find and download it as .jar file
But i also recommend higly recommend
https://llaun.ch/en it was original tlauncher laucher, more details
https://telegra.ph/The-True-Story-of-TL-05-21
Developer even publishing source code of his laucher.
But u need to download from ukrainian,russja,belarusia or other countries cause for most europe couries it gonna show DCMA banner from mojang,in other case it will load all files
U don't need windows version of cs 1.6.Valve ported all cs to linux,so so find native 1.6 version https://rutracker.org/forum/viewtopic.php?t=5735662
Also recommens u to try project portproton for launching games,most of my games works with 2 clicks https://github.com/Castro-Fidel/PortWINE
If u get used to notepad++ very much u can use reimplementation of it which cross platform https://github.com/dail8859/NotepadNext
Personally i am using pop os with Wayland enabled on my surface pro 3