I guess I don't see the harm in wasting the samurai's attack in the first round, as long as your bishop is casting a spell, your bard is playing an instrument, and your gadgie is using a gadget. That frost spell is still an attack! Even at low levels, a stinking cloud spell, a poet's lute, and a lightning rod can have quite an effect on your enemies.
And besides, don't you often have the case of your samurai taking his turn before the monsters move, in which case he simply defends, and you lose your turn anyway? This happens to me ALL the time, if I leave him attacking and the monsters aren't in range. That +6 initiative that Bloodlust gives him actually does more harm if I'm hoping the monsters will go before me and move into range. Of course I really worked on his speed and senses early on, so this could have an effect. But I'm sure glad he's able to get that Freeze Flesh spell off before anyone else!
I guess the other suggestion I would give with this party is to accept the fact that you're going to be more range-based than melee-based. If you are simply running up to monsters right away in the first round, you are wasting so much of the potential that this party has. No matter who I'm fighting, I'll sit back and spend at least one round, maybe two, throwing everything I've got at monsters, so by the time I advance forward they're either asleep or nauseous or insane or frozen or webbed or all of the above! =) If you equip your fighter with a double-crossbow (ranger should get multiple attacks soon enough), then you can be downright scary from a distance. Just wait until your gadgie can start knocking foes unconscious!
I would also suggest getting the Trynnie Ranger up at Mt. Gigas instead of Miles. I kept both her and Vi around for quite a while until they left me later in the game (I sure do miss Vi...the one change I might make to this party if I had to do it over again is use a Valkyrie instead of a fighter...but that's not a slam-dunk decision). With another ranger, you can truly rock from a distance...
And don't worry about your spells fizzling, that's how you learn! Are you increasing your sammie's wizardry by 3 every level as soon as you got it at level 5? Are you increasing your intelligence by 1 or 2 points every level until it's at least above average? (say in the 60s). As you scour the world hunting for spellbooks for your bishop (you ARE saving your Bishops spellpicks right?), are you keeping an eye out for other Wizardry books that your samurai can learn now or in the future? (or Alchemy books that your ranger can use?). Obviously, your Bishop will get first dibs on anything, but as you find duplicate books you should pick them up for your other hybrids to learn as well.
One final thought: you should see if you can pick up a wakizashi somewhere and build up your samurai's dual-wielding. It won't do much damage, but later you'll find an enchanted wakizashi, and with another weapon you'll have more chances to do critical hits every round.
Again, these are just suggestions to maximize your party's effectiveness at later levels. I'm not saying that casting level 7 frost spells will help you out much right now, but you'll be glad you did it later on! =)
Just my opinion...I'm having a blast playing this game, so whatever you do, have fun doing it!