Dont worry about asking loads of questions its the main point of getting better XD Rolling hops I dont really try or I havent measered the height neither the length but the biggest stair set I have found and done is 5...I could do more probably but I cant find any

Gratz on the stomach on seat and one footed riding. The idles get easier and easier.... Unispins take ages and ages to learn but are great once you learn them. The first tip is when you learn no footers dont do it seat in as you dont do unispins seat in so learn it seat out. Then just spin and spread your legs out and in again. Its one of those things were your not even that close but one day you get up and try and your really close then you land it... I learnt them before I had a 19" so on my 16" but I dunno if it helped XD
Oh and Ihave been unicycling since a few months after february I think... So yeah its all about how long you have had to practice these tricks

Good luck!!!