Let the Darkmoons be able to invade any non-hollow Darkwraith regardless whether they have beaten the boss or not. This is to counter those Darkwraiths who terrorize areas they have already beaten.
Hmmm.... as long is it doesnt affect my darkwraiths im okay with that.
Overall, decent changes really. Wouldnt mind any of them.

"Replace the +-10% level difference limit to invade as a Blade of the Darkmoon by being able to invade any Darkwraith from level 1 to your own level + 10%. Of course, the guiltier, the more hunted you'll be."
Now, I dont think this one would work.

A) It would basically make it so that low levels are thrust into battles they cant possibly win

B) (This one is moot if only concerned with pvp) if paired with the bosses dont matter rule, would give even less reason to be human in vanilla play. While not as important to a lot of people, the balance of human and undead in pve is very widely sided with the undead unless you're looking for pvp.

C) Instead of down to Lv.1, I would instead say that invasions up to -50% of your level would work perfectly fine. Level 100 darkmoons could invade down to level 50, and up to 7481040103. Level 200 down to 100, and so forth. This could improve the activity of the darkmoon covenant while shifting the balance less. 50% may be a bit too much though... maybe 30%?

Remove regular base damage for elemental weapons and replace it with scaling based on the elemental damage. The scaling part will become the regular damage stat. This way elemental weapons can no longer be exploited by level 1 darkwraiths or abused by players who dump stats into Vitality or other support stats.
So, what do you mean by this? Like, say fire would have strength scaling? Lightning dex? If so, that's fine. But if say a katanas dex scaling carries over to an ele weapon is your idea, then yeah, I very strongly disagree.
Elemental weapons have very little purpose really. Their main point is to allow people to use weapons that they don't have the stats to get the scaling with. Let me use my trusty shotel as an example. It's a key weapon for my 50 strength forest hunter, as without it turtling gankers would be far more annoying unless I resorted to backstab fishing. This would seriously limit weapon variety and weapon utility, greatly shifting the balance of which stats more viable. I'm not sure of a different method to fix the Lv.1 prickwraiths, but I know this wouldnt be the right way to go about it.


ONTOPIC:
So, soon I will be reaching 50 strength... and then, THE FOREST WILL TREMBLE!
Dragon king greataxe + hidden weapon + R2 = DESTRUCTION!!!!