Most stuff on Steam runs very well these days. Anti-Cheat and DRM are the main reasons stuff doesn’t run.

Not in legal trouble but the airline might decide not to sell tickets to you in the future.

Balancing is the job of the GM.

And some systems make that job easier for the GM than other systems. Winning all the time without challenge is boring. Getting TPKd every other session does not feel good. A good GM should hit somewhere in-between. So you either have a system that helps you do that or you really need to have a lot of experience.