Del-Dredd

Its because you are using a controller ie not many buttons, on Pc with keyboard and mouse, the interact is an entirely different key so not an issue.

Installed fine for me from Epic no issues what so ever, no crashes or anything yet either. Maybe something system wise is stopping you.

Obviously they did not even try as remapping keys is very easy. Options / Settings / Controls Under Keyboard and mouse click on Edit Keybindings Button. Very simple if you actually look.

Messed up Launcher creating dodgy folders on install sounds like it. Luckily no issues here on Win 10 and Epic Store version, installed on M.2 NVME drive.

Try pointing cursor at the dialog first before clicking X maybe.

I think Mods will only go on certain Weapons, it does not tell you that though. You can see what Mod types are available for the Weapon though. It could be you have to have a specific Mod for the type of Weapon. I had a Suppressor Mod (to make weapon not as loud) but it would only fit the Grenade Launcher, even though it would be more use on Revolver or Assault Rifle you would think.

Probably if you looked at the DRM used you would have understood, it is an Epic Games Launcher no matter where you buy it. Just Like Red Dead 2 will be on Rockstar wherever you buy it.