"Couple of problems. The Ninja hardly does any damage.."
Well Tryton is adjacent to the Rattkin Tree, home of the CoC - once you get that, well your Ninja will be quite a bit more effective
"the Samurai keeps on missing with Bloodlust."
Basically it will be his Str/Dex and sword skill that determines how often he'll hit. But the spell "enchanted blade" will also help out alot - the problem with an all hyrrid party is it will be a while before you can get that and the other buffing spells up at level 7 reliably.
"For both of these I've given them a little Strength and then concentrated on Dexterity, Speed and Senses. When the Samurai does hit something and it does no damage, it says something like no penetration. What attribute do I need to penetrate their armour, I'm guessing Strength?"
Str + Dex are the best, plus having Enchanted Blade up. Senses is almost worthless for them really.
"While still in the Monastery, the Samurai did have about three lightning strikes. I'm sure it's been asked several times before, and I apologise for asking again, but what causes the Lightning Strike?"
That's a question no one has ever answered with a better response other than "they're random".
"Another problem is that I haven't got anybody to identify anything. I'm going to allow my Monk to do the identifying as it is a Mental spell, therefore building up his Psionics and Mental realm. I'm also trying to get him to be the fastest party member so he can cast Haste when he reaches spell level 4. Good ideas?"
Yes and Yes! =0) If he's going to cast haste alot, skimp on raising your other characters' speed and senses. Those would be good for the monk as both effect initiative, and you want the haster to be able to cast haste quickly.
"On a related matter, is there any way you can get one of your party to do all the identifying and so just have them building up their Artefact skill? It seems to be quite random at the moment. Everybody seems to take it in turns to identify things."
I think they all try to ID things when you right click them, don't think there's a way to select only one.
"One final thought on formations. At the moment I have the Valkyrie, Ranger and Vi right at the back, three melee fighters in the centre and one on the left wing. Can I improve on that as the left winger cannot reach when the monsters attack from the right?"
Well none of your characters will be weak in melee, so you need no special protection for anyone in the formation. I would put either three in the front and three in the middle, or three in the middle and three in the rear, same difference. I would put the Valk, Ranger and Monk in the back (and I'd have the Monk using a staff, I know some people prefer MA but there are some sweet staves and they're extended weapons). Then your rear guys will all have extended range melee weapons and the front guys short range melee weapons, and you won't have flank issues. Really the flanks are more useful to protect weaker melee types (ie, pure casters).