I don't see why they have to be handled the exact same way FFXIV

[ffxivfans]

Cooldowns like that would need tweaking (although with this idea Block would likely mitigate less damage), but I still think blocking and evading magic damage should be possible. Maybe not parrying, since that makes less sense, but it would be possible to balance. Especially since Dark Dance could be made a lot better with changes like this (I know it's really good for Uplander Doom but I feel like that's really the main place it's useful in raid, although I could be wrong about that).

The reason we can't block magic is because magic doesn't have a directional source. Meaning the game doesn't actually calculate which direction a magic attack comes from, so it CAN'T be blocked. This is FF14GilHub the reason why casters also have the lowest Accuracy requirements, and why they're exempt from Ravana's "Seeing X" mechanic. So if you're okay with casters having to deal with different accuracy caps and worrying about positional orientation, then you can have your magic block.

Also, don't get me wrong, I'd like to block magic too, it makes sense since I have this damn shield, but I also accept that the concept is not for this game.

I don't see why they have to be handled the exact same way, to be honest. Monsters aren't capable of blocking, so it's not like it would be confusing. Also there's technically physical AoE damage in the form of cleaves that can be blocked/parried, as well as one offs like the AoE's from meteors in T9 that can be blocked/parried. So I see no issue with at least some magical attacks (specifically attacks coming from the monster towards the tank) being blocked/parried.

Actually if you go fight some lower level shield-bearing Ixal, they will block you. The reason those can be blocked is because they have an attack orientation. Think of the damage as a wave, rather than a cleave being placed on the ground. If you face away from any of these, you will not block/parry.

As for AoEs that are dropped on you that can be blocked/parried, the game registers the direction as the direction the enemy is from your face. Magic doesn't go through this check, and therefore the damage is technically registered as coming from your center (almost inside of you, so to speack), and can't possibly be blocked.

There isn't really much point in trying to future-proof your relic for 3.4 (assuming the Parry changes are even going to be in 3.4), because it's almost definitely going to lag behind other weapons you'll have until 3.5 or 3.55.

You'll probably replace the relic in the first couple days of 3.4 with a weapon from the next trial (expecting a trial with i250 weapons, like Buy FFXIV Gil Sephirot had 220 and Ravana had 190), and if you keep up with the next tier of raids, you'll probably be right on the cusp of upgrading your tomestone weapon from 260 to 270 by the time they let you upgrade the relic to 260. The relic won't really catch up again until they let you upgrade it to 270, or even 275 if you've cleared the next raid tier before 3.5. (And keep in mind, if the Parry changes make it in, it really won't be possible for there to be situation like the Lore axe where secondaries make the weapon really terrible for its iLevel)
That's more than enough time to fix your stats once you know how they work, rather than second-guessing yourself and trying to alter it now.