Any help I can get with these, I'll be super grateful. I've tried searching for answers for these but I guess, if the answers are out there, I can never make my questions specific enough. Even a "no, you just can't do that" would put me at ease!

1. I can remember the "gamejam" mod showcase. In it, dual-casting different spells to create a third, unique effect featured. Is this at all possible // what are the limitations? I'm assuming, since I've not seen a single mod that features it, that it's just not possible... but I remember the video! It happened!

2. Could you make a spell/magic effects, where it has different effects depending on (a) which hand it was being cast from (I've tried playing around with the HasEquippedSpell [hand/voice/instant] and the other one which looks for both the specific spell name and the place that has equipped it - but obviously having the spell equipped in both hands screws that over. Ask me to explain in further detail if I'm not making sense here.

and ( if it had been dual cast. I know the dual cast kind of works, just from the vanilla game, it exists as a perk for destruction tree.

Hmmm, I'll explain 2. a bit better. Imagine if, I wanted to make ONE spell. Cast from the right hand, it would release a stream of fire that did fire trap. Cast from the left hand, it released a stream of lightning that healed. Dual cast, it released a stream of frost that spawned the Frost Barrier Hazards Impact Sets whatever they're called (i.e. the Wall of Frost spell). That was all random by the way.

The way I currently see it, I can't even make the dual cast one work in this example (despite IsDualCast = 1 working to make Destruction spells stagger when they dual cast in vanilla skyrim), because those Hazard Impact Set things are ALWAYS spawned regardless. This is the same as well, for example, if you wanted to make a Perk that, if unlocked, it would cause the Incinerate spell to explode like a Fireball. Once you add the "explodey part" to incinerate, and then despite giving it the "isperkunlocked/whatever = 1", it'll always explode anyway. Just like the hazards will always be spawned, even though IsDualCast=1, and it should be returning 0.

3. What is it that makes Summoned Creatures disappear and not leave a corpse upon death? I tried making one for one of those Corrupted Shade things from the Meridia quest. I virtually copied everything from the vanilla "Summon Familiar" spell. The "Corrupted Shades" still leave their "ghostly remains" on the ground when they die (and it's uninteractable).

4. Finally, not really a CK focused question, but a weird thing I've noticed...

It's kinda difficult to word, so this is what happens:

-I have a staff equipped in the character's right hand.
-The staff spell is a "fire and forget" as opposed to "concentration".
-I have a spell equipped in the character's left hand.

During and while the spell for the staff is "charging", the visual effect for the spell in my character's left hand floats up and leaves the screen. If I start release the staff spell, the "floating spell" instantly returns. And if the spell and staff are swapped around, then this doesn't occur.

Obviously, it's not a huge issue, but one day it really got to me, so I went on the nexus assuming to find a mod that fixed the problem, though nothing showed up. So I checked the uesp page for staffs to understand the bug... nothing mentioned, nothing on the talk page either. Same on the wikia. A quick search here and in other forums brings up no similar results.
At this point I was/am baffled. I am not used to experiencing unique bugs (especially ones that are prevalent in every playthrough of skyrim). I am hoping I am completely blind and the solution is somewhere obvious, but I'm pretty certain that it's not.

It's not a gamebreaking issue. Up until recently, I never really used staffs either.
But now I feel utterly compelled to resolve it. Could this be a problem from when I initially downloaded Skyrim? What would be the "fix" for that?

THis is a lot bigger than I had hoped... and these all might seem really mundane to most of you. If that's the case, I'm not after you to "do it for me" or "hold my hand" (though actually I wouldn't turn my nose up at it, lol), you can just go "stupid Denar, here's a thread that actually explains it, /point"

Anyway, if I can get just one of these "solved" I'd be reaaaally grateful. Thanks guys!