Thanks for the report!

/u/d3rr take a look here if you don't mind, this person has found a few issues with the app.

We've been thinking about making /s/subscribed the main page, but since we have a small community we don't want to split it up anymore than we need to.

The blocking sub behavior is intended. It's blocked on /all and /subscribed but you can still access it directly if you want.

I don't think the desktop even has a block subreddit option, it is only part of the app. Ideally you'd just unsubscribe to it and it wouldn't appear in your subscriptions. That's the system we originally intended, an opt-out system where you are by default subscribed all subs then you choose the ones you don't want.