Just off the top of my head, and if I understand you correctly - unless you're tracking individual account gold vs server gold and adjusting per account, this could easily end up punishing new starters as they try to accumulate gold at the beginning. It could also end up creating gold barons where someone has a lot of gold, server drops less accordingly, creating a bottleneck based on a few high level accounts that just happen to be sitting on a Smaug hoard.
If you go individual acct vs server, then you're effectively attempting a gold cap for each player. Accumulate x amount and that's it for j00, no more gold til you spend some! Depending on what they want the gold for it might end up being rather annoying (eg a new gold sink to craft, maybe you want to save up enough to do a big crafting session but the game will only allow you to save enough for 3 skill points then back out you go farming).
Not sure that "infinite" gold is a problem per se. Gold acquisition only becomes a problem imho when it becomes an easy route to winning or imbalance. Since this is essentially a single player game with no AH, right now it makes no difference at all how much gold someone has.
With an AH gold becomes an interplayer currency but unless you're intending to implement a gold-bought I WIN button (or possibly crystals/gold exchange?) there's no intrinsic value to any currency and again, it doesn't matter how much gold is washing around in the system. Even if Epic Weapon X is on sale on the AH for 50 bajillion gold it doesn't matter - Epic Weapon X doesn't confer any imbalancing player advantage except perhaps to better equip them for a run on the leaderboard (and not everyone cares about that
).
Just my ...... 2gp