The UR deal in shop costs 5000 nutaku golds. However, you get 2 free UR from the missions.
You should evolve ASAP.
The user pack is indeed bugged. Either a wrong tooltip or a bug, but nobody got plat ticket from it.
The reset is indeed daily, but sometimes, missions are limited to 10 times or 3 times.
I don't think cash can help for the monthly reward, it is for when you missed a day. However, the character is not exclusive, she exists in the gacha aswell.
Also, dont worry too much about the invite code, you will swim into gold tickets.