I think that when your enemy attacks you and your shields equal up to more than 100%, than the attack should be absorbed and it should reflect how much more percentage you have. Also, if you have a minion after a battle ends with a boss, then your minion should be able to pick up a boss drop depending on how much it participated. I hope KI thinks about that!
Ok, these ideas sound good on paper, but when it comes to coding things for gameplay, it's a different story.
1. If your shields add up to more than 100% and were to absorb and reflect damage, the enemies would be able to get the same benefit. Aside from the fact that it would completely break class gameplay for ice wizards, there are other flaws in the concept. For instance, what happens to attack boosts against you that might add up to 100%. Should that mean the opponent outright defeats you? There is nothing wrong with the current setup. If you have shields and are taking minimal damage and still lose a duel, you have some problems somewhere.
2. You summon the minion, the minion gets a drop, where does the drop go? I assume back to the person who summoned it. Not really fair if you play in a group, as only one person can summon a minion, then only the person that summoned it would be able to get extra loot. Seems like you might be looking for a shortcut through farming for your loot, so doubt this one's feasible. I don't use my minion spell because it eats my pips and I don't need it. I guess because of this, I should have a disadvantage at getting boss drops, or at least according to you.