I feel like its really lame that in some ways, hopping around on a bunch of alts is required if you want to be truly competitive. Though this nearly always been the case in pvp mmorpgs, in AO it seems somewhat more game breaking.
1. Because you are allowed one private island for each character on your account, you can provide all your farming needs yourself and thus eliminate the intrinsic value and need for specialty as well as the market just by logging in a few minutes per character each day.
2. Considering the passive income of personal islands over time and tax-free buildings, its reasonable to assume some might find greater value in buying a bunch of alt accounts to sell horses and oxes everyday and whatnot rather than what they might otherwise do,Buy Albion Online Gold to convert into silver directly, which unlike personal islands, has a finite value.
I would suggest diminishing the power of alts by either only allowing 1 character per account, or only being allowed 1 personal island per account. This way people with money to burn and several accounts won’t have such large advantages.
3. Alts can be used to modify buy/sell orders at romote locations, thus eliminating travel costs that other traders pay, and freeing up your main to do other activities. Not a big deal for most people but it does create an uneven playing field for traders. For this I suggest that the the ability to create buy/sell orders for tier 4 items and higher require an equivalent adventurer level.
4. Scouts. You can just leave your alts all over the place as tripwires to locate escaping Oxes, warn of incomming pks into the dungeon, you name it. No idea how to deal with this one, but reducing AO Silver to 1 per account should reduce their desirability. Special roaming elite MOBs with large aggro radius that will send you to town when they kill you could help a bit to combat this.
5. Alts can also be used as a bank to store items in dangerous areas. For this I suggest increasing the logout timer for the disgustingly overweight players.
6. some other nasty thing. Like 2v1’d a guy with my alt account b/c you can play with one hand..
Edit: In before an army of alts comes in to tell me that alts are fine and that there is nothing stopping me from buying a bunch of alts too.