Thanks for all the help. I got past Orthelios in the end by using the green button to seperate my party and then used Christoff to lure out the nosferatu one at a time, then my party took turns feeding on them, and then my Brujah sidekick actually killed Orthelios by feeding on him (he had a higher feed than my other 2 as well as better strength, which is why I used him).
As for stats, I'm increasing the stats pretty regularly (after playing bloodlines I know that its important to raise stuff like stamina) and I have decent armour (all 3 have leather armour, light helms and some gauntlets). Christoff has an exquisite broadsword, my Brujah sidekick has an exquisite claymore, and the girl has a fine rapier (but I tend to keep her out of melee if I can cos its seems her stats are more geared towards disciplines). The actual combat isn't the problem, as I've got the hang of that. Its the party control that I was struggling with. If I leave them to it they just use all their blood and end up frenzying but if I turn off the auto discipline function, then its a nightmare to manage them all. Its a pity there isn't a pause button like in BG2 and the Kotor games. It would make party management so much easier. Now I know how to split them up its a lot more manageable though so thanks for your help.
@Acleacius, the first thing I did was install the patch
