Doing the relic properties now, there are a few things you should be aware of.
Infect - 1/2 + Absorb Poison (you get this way too late in the game)
I don't think this will actually work, I've never tried it before though.
Nuke - ignore Mblock
Meteor - ignore Mblock
Flare - 1/2 Fire and/or 1/2 Wind and/or ignore MBlock
You do realize this is now ignores evasion right? The evade patch fixes this, this is the sniper sight property, it's used on the lucky ring.
Tornado - null Wind and/or resist Weak + once weak, always weak
Cure+Life spells - add Weak status
I don't know why you want these to resist/give weak (Near Fatal) status, it doesn't actually do anything except make the character crouch down all the time, pretty pointless.
Scan - 1/2 all elementals (the idea is to remove all weaknesses on yourself)
This seems way too overpowered, unless you get this one later in the game.
Imp - resist Imp
How about also having it give a nice defense boost while the character wearing it is an imp? I don't know when you get it so I'm not sure what would be good.
Slow2 - prevent back attack
You mean the run from side attacks option the back guard usually has?
Rasp - (if it didn't have the HP/MP boosts.. or in addition to those boosts) adding one of the MP reduction options
I think the boosts are enough.