Is there an achievements guide? I am very confused as the subetawiki guide and actual achievements list only has a couple hundred but I see people with 1600+ achievements. I googled it and saw a board that had a link for a guide but it was broken.

I'm afraid there isn't, as far as I know. I've been trying to work on one, but its tough. The sheer number of them makes it pretty complicated.

Your best bet is to ask questions about specific achievements or groups of achievements.

There are over 2000 achievements. Many of them are "tiers" so there will only be one achievement listed. Check the Battle Quest achievements, for example, under Games->quests. There is only one listing, but 16 achievements in total.