Thanks a lot to all friends and the forum members to keep me motivated to go for this line. Considering the obstacles created by GI and their support philosophy it was mainly the community to keep me to play the game.
Every time you finish level, you get this promotion message with offer lasting 2 hours. As I had one Pilot's manual (last 2 hours) I was forced to make all the openings within 2 hour to get the most out of the bonus. That was terrible as it interferes with the area where you need to touch screen...
Having the ads for purchases filling more than half of the screen? That is very inconvenient. I was expecting it will go to max 2 columns, but not 6 extra columns. Luckily had no more collections available or I would not be able to send planes at all.
That was easy. Pilot manual, alliance bonus and jar of diog => total 330%, so from one collection (e.g. lunar race) you can get 3300 exp. I have total 380 collections to grab and that results in over 1,25M exps. All about patience and proper planning.