
I'm going to start off with this: Bound Weapons.
I have been doing a play-through using only Bound Weapons, and I can say, it is a lot of fun! But, they feel really....awkward.
1) The duration of them is "okay", 2 minutes, then 4 minutes with dual-casting. So that's not terrible, but it would be so much more tolerable if there wasn't such a huge delay in the cast. After casting, you have literally about 4 seconds before you can even use it, or even pull up your shield to block. I haven't tested the Bound Dagger, or the Bound Battleaxe. The Bow seems to be slightly faster at 2-3 seconds. And the Sword at 4 seconds. This is huge when your weapon vanishes right in the middle of a fight. So lowering, or even removing this "delay" would be optimal.
2) Dual-casting Bound Sword always puts it in the left hand. This makes it impossible for a "sword and board" style while trying to extend the duration of Bound Sword. I see no reason for it to be in the left hand. Either way, you can still dual-wield, so this won't be effected.
3) The damage of Bound Weapons is not reliable. The amount of early game damage these things can pump out is HUGE, especially the Bow, the arrows they give are equivalent to Daedric Arrows. And the spell can be found, and used as early as Lv.1. Also, something that adds to the damage of early game Bound Weapons, is the Perk: Mystic Binding. Which can be acquired as early as Conjuration Lv.20. (Breton start off with 25, so by Lv.2, they can have this perk.). So it's pretty early on that you can max out on the base damage of Bound Weapons. So, my idea, move Mystic Binding up to Lv.40, above Soul Stealer (Lv.30), and under Oblivion Binding (Lv.50). Also, if possible, add in another perk for a new Lv.20, it could be something like: Increases the duration of Bound Weapons by an extra 120 seconds, and Bound Weapons now do not vanish after sheathing. So this 120 seconds is added on after the dual-casting time. (base 120 seconds * 2 for dual-casting = 240 seconds + 120 from Perk = 360 seconds.)
I also think since Bound Weapons can't get any stronger than how they are (other than leveling One-handed, Archery or Two-handed), and you can't enchant, OR smith them, they fall off pretty hard once you start progressing. The base stats on Bound Weapons should scale with your Conjuration Level. So at low levels, Bound Weapons will be doing damage more appropriate to your Level, and as you level Conjuration, they will become stronger, but still not as strong as an enchanted and smithed weapon.
TL;DR: My main concerns are removing the delay from the after cast of Bound Weapons. And making dual-casted Bound Weapons appear in the Right-hand.