First of all, I hope Blaine’s hernia surgery goes off without a hitch. We’re pulling for you!
House rules are great. It's all good and fun. Just for my own curiosity, here’s how I understand how 2nd ed D&D works for spell-casting and initiative; if someone else knows better please correct me.
There are lots of ways to do initiative, but it gets done every round. The players decide what they’re going to do, the DM decides for the monsters and then you roll for initiative (1d10) to see the order of events, lowest number goes first.
You can do a roll for the party and a roll for the monsters, or you can roll individually for PC’s, NPC’s and groups of monsters.
If you decide to use casting times and weapon speeds, you add that number to the roll. So if Winter casts Magic Missile, the casting time is 1. If Winter rolls a 5 on a d10, so his initiative would be a “6”. If Lyra, swinging a short sword (weapon speed 3) also rolls a 5, her initiative would be “8”. Dag, with a battle axe (speed 7) rolls a 4 for an initiative of “11”. Houg wants to hide behind a bush and rolls a 2. The skeletons are using their claws, (natural weapon, medium creature, weapons speed 3) and roll a 6 for an initiative of “9”. These numbers could be modified further is the DM wants
So the order of events would be:
Winter casts magic missile
Lyra strikes at a skeleton with her short sword
The skeletons attack
Dag swings his axe
Next round the PC’s decide what they’re going to do and roll to see who gets their action first.
I don’t think you need to roll to attack with spells. You either cast them or you don’t. They don’t “miss” because of the spellcaster missing a roll. Priests have a chance of spell failure if their wisdom is below 13 and both wizards and priests can be interrupted if they get hit while they’re casting a spell in which case the spell doesn't get cast and is lost. Once the spell is cast, it’s up to the targets to try to resist the spell with either a saving throw or whatever defense they might have. Magic missile has no save and can’t miss so it’s always going to do something.
The exceptions are “touch” spells like shocking grasp, where the spell just “charges-up” the PC’s hand or weapon. That’s the effect of the spell. Houg still needs to land an attack (touch) on the opponent the next round to deliver the shock. If he misses, he stays charged for as long as the spell allows.
At least that’s how I understand it. Of course, Blaine should be able to do anything he wants; it’s his game. I think Sarah was getting a bit frustrated with having to roll for an attack using the ring, when it shouldn't really have been necessary.