Need Advice on Potential Spell Mod

I am considering adapting some of the spells and abilities that I have previously scripted for NwN into BG2:EE. However, I am not sure of what is possible in this engine with the currently available opcodes, etc. I would like advice from experienced modders about whether the following types of abilities are doable in BG2:EE:

1) Effect that changes the next spell you cast. Examples: "Your next spell lasts twice as long," "Your next spell also deals +2d6 fire damage."
2) As 1 above, but over a duration. Example: "For one turn, any spells you cast heal you for 2d6 hit points."
3) An effect that modifies a specific spell. Examples: "Ice Storm spells cast by you deal an additional 1d6 cold damage," "When you strike an enemy with Chill Touch, they must save vs. death or die."
4) Effects conditional on the target's status. Examples: "Deal 1d10 poison damage + 2d10 additional damage if the target is diseased," "Target suffers 2d6 magic damage for each Enchantment spell affecting them."
5) Copy effects from one creature to another. Example: "Any enchantments affecting you are mirrored on touched ally."
6) Effect that reduces (but does not eliminate) miscast magic chance. This could be used to simulate Still Spell feats on the vanilla armor system, for example.
7) Effect that changes the type of damage dealt. Example: "Damage inflicted by your spells is converted to fire damage."

Thanks in advance for any advice.

-K