There's not much to joining religious groups at this point. Anything meaningful to come out of it will have to wait. But you can do it.
I don't have a timeframe on roads, but they'd certainly fit in with armies. We'd like to have outlying farms, and we were talking recently about how to improve the site structure will sprawl and outlying locations, but that might have to wait for the Caravan Arc, when sites starts tracking resources.
Fortress retiring isn't going to come in with armies. It's not scheduled anyway.
Adventurers won't be tied into the world until the Scenario Arc. At that point, it'll try to weave you into the world if you so choose. The Relationships Arc is for creating families yourself.
As for hours, I still do forums (like I'm doing now) and email on the weekends, and that can take an hour or two depending on how many threads/emails there are to read and respond to. I also do that during the weekdays... there's also cooking and shopping and errands and all that... the rest of the time is spent on the game on weekdays. Last week I managed 10-12 hours most days (sort of a 6/7PM to 5/6AM schedule), though it can vary wildly if I have something going on (like the interviews that popped up, which sort of suck time up all around them). On weekends, time is spent on a combination of lazing about and working on other games.