Maybe account-wide repercussions? For example, bonus AA requires focusing on one character. E.g., you earn an AA bonus for every day you log in to your main without logging in on a different character.
Or: You can claim a limited amount of bonus/faster AA, but if you do, it slows down the regular timer or AA rate. That'd let people get critical AA feats out of the way, but at the price of fleshing out everything else much slower.
Just need to greatly increase the aaxp for lower levels so that someone who plays their character to 80 has enough aa points to get the required ones. Additionally the aa timer could be enabled at 20 instead of 80.
This AA point disparity doesn't need to have the VETs loose thier edge ; have an updated system that matches player stats AND AAs with there peers ~ the new players get mixed in with OTHER new players in minis and work their way up ~ or do Away with PvP AAs all together ; keep PvE ones for the Raiders
IMO the best course of action is to remove the requirement to play altogether.
New players have the problem but so do vets. I level a toon to 80 (off-line) and then park it for 3 months just to time train the aa's required to be able to do a 6 man which is totally stupid.
You dont want to give new 80s 300 aa's as it will upset the vets who have put in hours attaining thise goal. Similarly the new player wont immerse themselves in the game if they are gifted so much.
The real issue is the barrier to play. Resolve this by removing it.
Swap out these required aa skills such as Steadfast Faith and make them just normal spells / abilities available to everyone of that Archtype upon reaching lvl 80.
Replace these removed AA's with new ones that are desirable but not essential like +5% dmg or + con.
Problem solved.