If i have, let's say 100 armor rating, and a shield, if i cast Dragonhide before battles will i be invincible?(damage reduction beyond 100%)
And does [insert name]flesh stack with Dragonhide?

No, damage reduction is capped at 80%

But i read somewhere in the wiki that a player could reach 96% damage reduction.

Your damage reduction maxes at 80%, with an armor rating of 567.

Unless I am mistaken that is when you have maxed out the damage reduction from blocking in addition to the 80% from armor. First you reduce the damage by 80 or 85% from the blocking, then 80% is subtracted from that again.