It‘s not intuitive, but you can find your subscriptions in the settings
In terms of features kbin is kinda lacking, but considering that it‘s basically existed only for a few months and has been developed by a single guy it‘s pretty impressive
I‘m sure new features will be added relatively quickly now that a lot of people are willing to help out
As far as I know that‘s because earlier in development the boost actually was the upvote, but now it‘s as you‘d expect it coming from Reddit
But I think the reputation system just hasn‘t been adapted to this yet
I‘ve just heard that from someone else around here, so take it with a grain of salt