ty

No
Iirc only the stronger aura will have effect

This, pretty sure this works with every aura.

And i've heard if your conviction is bigger than Uber mephs it cancels it also. (if so, does this work for every type of monster or is this just uber meph???)

From basin:
Equipping more than one item supplying the same aura will supply that aura at a level which is the sum of their levels, regardless of the items used: a Barbarian equipping two Lawbringer swords (Level (16-18) Sanctuary Aura When Equipped each) supplies level (32-36) Sanctuary.

Auras granted by items equipped receive passive bonuses including synergy bonuses, but they do not apply bonuses to other skills.

Players and mercenaries can supply as many different auras from items as they are able to equip. However, items count as a separate source and will not enhance the same aura supplied by a Paladin or Desert Mercenary: only the higher level aura will normally be supplied.