There’s just two of us, yes.
90% of the time we are working on the next update, sorting out bugs, and also running the business from an admin point of view. We also do our own system administration, web site management, have to test all the builds before they go up, etc.
We try to check in every few days, and reply to anything that seems important, but sometimes we end up focusing hugely on whatever the next update is.
Our update process is that we try to do a decent-sized bug-fix update every week, alternating between working on that and back-end stuff for the next major Early Access feature update, which have been mostly planned out, but with specifics shifting based on what we read on the forums and in emails.
We tend to reply more to emails than forum posts, but even then we get enough that it can take us a week to reply sometimes.
Much of the time we skim them and see if any bugs are frequently reported, and shift our focus based on that - obviously, if after one update we’re getting a half-dozen people reporting a crash, that becomes our top priority.