Well steamservice.exe is causing The crash, and any game that does not rely on that process can be played without crashes after you disable/delete steamservice.exe. I know for a fact that VAC uses it, thats why you cant delete og disable it for games that uses VAC. Other games _might_ work, especially singleplayer games. Non-VAC games crashes without steamservice as well, I know, but not all.
so if you play some obscure singleplayer game on steam, disabling or deleting steamservicr.exe _might_ fix Your problem. I play CSS/CSGO so I dual boot win 8.1 for now :)
and no, its not The bootstrapper, its first steamservice.exe that crashes, then bootstrapper(steam.exe) and then Your game.