The only real issue with any aftermarket heatsync/fan is the fan's clearance of tall memory sticks. (and occasionally, tall chip set heatsyncs) But the 212 sits quite a bit higher than its big brother the EVO. Plus, with the naked memory sticks you have selected, there will be no problem.
Even with a CPU intensive game, the graphic card can still be the weak link and may be the issue your friend is experiencing. Even at stock, the FX-6300 should have more than enough to handle that game with the HD 7870 @ 1080p. Another issue if you are gaming on-line that folks forget about is internet and server traffic. That may make it feel like the PC system is sluggish when it's really not.