i mean when i use the trainer and im done with it in task manager i still see wemod there in background processes, so would it be safe to use this on single player games and then also be able to play games like team fortress 2 and left 4 dead 2 while its closed?
Yes as long as you dont start the game through wemod. Start them from steam should be good
If worried just end all wemod in task manager before you play online