Your combo should work fine. I dont recall if REBUG version 3.41 had any bug issues with certain games or not. I know it cant play Uncharted 2 on REBUG 3.55 right now, not sure about 3.41 version though.
Yes Hmanager comes with a payload and its a great manager to use...I used both when i was on 3.41. Now that im on 3.55 i use Irismanager mostly for games (basically hmanager) since it has decent discless compatibilty but i use multiman to handle all my ripping and file management. Still not like it was on 3.41 but its good...
for you being on 3.41 still i recommend using hmanager for playing most games and multiman is great for pretty much everything utility related like ripping your discs and file management. It plays games great too, i just use Iris out of habit cause it has pretty decent discless support. Usually just comes down to preference. I suggest trying both.
As far as I know, my ps3 has never had an undetected error.