Re: Hl2.exe has stopped working
If you were running tf2 natively in Linux steam instead of wine or Windows there would be no hl2.exe (it uses hl2_linux). Although, Linux steam games probably work best with nvidia graphics.
You do not lose any achievements/items if you fresh install steam and tf2 on a different OS (or computer) because that info is stored in the Steam Cloud. I can confirm that because I installed steam and tf2 from scratch (without copying anything over) in Win7 when the Linux partition of my drive failed, until I replaced the drive, and in Win7 in a new laptop until I figured out bumblebee related optirun parameters for steam games in 13.10.
i5 650 3.2 GHz, 8 GB, nvidia GTX 750 Ti, 32" 1080p | i7-4700MQ, 8 GB, Intel HD 4600/nvidia GTX 765M, 15.6" 1080p | etc.