1. Maybe there will be a competition, but only regulator knows when. In my opinion to enter in MUX5 is easy, if you are a local TV company (those 2 empty TV channels aka "tests" are reserved to local TVs), but Pidbuzh won't ever have such TV company....maybe someone from Truskavez or Drogobuch, but it's not very realistic. Ex BankTV, in my opinion is reserved to some goverment TV, so no competition for this place. Xsports...i don't know, i never heard that some TV company is happy to buy that license (yes, you can change TV company without making competition, and it already happend in ukrainian DVB-T2).
2.No there are no specifics.
3.There is only one antenna system for all DVB-T2 MUXes. 36 TV channel migh be "dirty" or amplifier is working with less power.