If you look at it at a pvp point with caster vs caster, level does not matter after a certain point depending on class/build, yes.
Gear you probably want on your character is already equipped if we are considering HLD.
Main benefit (if they fall under the 'fake' level) would of been the leveling up with stats for caster vs caster (health/mana).

However, melee characters are different.
The formula takes into both the attacking and defending characters' level when doing the calculation.

Don't worry, most people that are reading or getting into building characters will know what they are doing and begin to learn.
Also, try and structure what you type.