Like can I enchant a weapon with a useful alteration or illusion enchant?

There are fear and frenzy spells avaible. Ones I can find that aren't destruction: Banish,turn undead,paralyze,Soul trap,

Nope, there's Paralysis for Alteration and Turn Undead for Restoration.

Then there's Fear for Illusion, then Banish and Soul Trap for Conjuration.

EDIT: Ninja'd and also

There's a frenzy enchantment for weapons?

How high can the fear spells go, and does the paralyze glitch out if the enemy is killed?

Depending on your enchantment and what alchemy/enchanting loops you use,I think the cap is 95. You can make dragon priests flee with turn undead if you have nercomage and the most powerful turn undead spell.