Congratulations. When little kids ask me how I ride my unicycle (something I get quite a bit, given I often use it to pick my 5yo up from school) I often say “magic”, and there is a touch of truth in that - with practice you learn to do stuff without even being aware of it. Just keep riding, and you will learn how to do it.
On your third goal, have a look at EASY freemount for Newbies really works! - I learnt to freemount that way before I could ride as well as you can. Admittedly it is in a way a dead end - I no longer use that technique at all - but not only does it give you a lot more freedom very easily, it also helps a lot with learning the technique and confidence for other freemount techniques.
Going back in the thread, I only skimmed the off-road video you posted, but from what I saw I reckon I could ride pretty much all of that after 9 months of riding - I even reckon my chances on one of the bits he fell off. Definitely feasible for you far sooner than you expect. I do agree with aarons that he should be wearing a lid though - I would be for riding that (even though I’m not an advocate of lots of protection - I’ve never worn knee pads and don’t regret not doing so).
Oh and regarding riding in sandals, I’ve actually ridden in flip flops - can’t say I was all that comfortable doing so though!