The rolls are driven by stats, and I have plans to eventually allow players to gain levels and upgrade stats, but it keeps getting bumped back in priority for other features.
There are no plans to introduce combat right now.
I have experimented with an Android build, and it worked reasonably well aside from the fact that the interface is too cluttered to work on a phone. But I might do a tablet-focused Android build in the future. It could also be a good way to get the game running on Linux, which is another request I've gotten repeatedly.