What will get you banned? Using any DETECTED multiplayer hacks/cheats while playing on VAC Secured servers.
What will not get you banned? (unless VAC terms changed in the meantime)
.cfg Editing
Texture modifications with exact size, hex header and CRC32
Using mods in private match while VAC = 0
AutoHotKey Scripts
External Crosshairs/AutoQS/etc.
RPM
VAC Unknown (as for now)
Some people claim that they were banned by VAC bcus of using Singleplayer trainers but VAC ban relates only on Multiplayer which makes this ironic.