I dont like the change to lowemon QQ
but adding to your 6):
I think they should make standart events. One event screen for each race. For example, the dragon island wil have 3 islands. One with the fire booster, driver and small vamper respectivly. For each race there will be screen with 3 islands with those three. They would be standard like aegiomon quest.
My own suggestion:
Digimon have more then one leader/main skill. You can swap between them. This would make them alot more versetaille. And if thats abit too much, maybe a passive skill will do. Boosters could have the passive skill that they wil increase their teams defense and attack if theyre from the same race by 30%. 10% after each turn maxing out after the 3rd Turn.
Im not too fond of the buddy system. What if they made it so you can choose 2 leaders instead of 1 of your own team. They could make another way to have friends more inportant. Maybe give the option to set one buddy as team member but not as leader.
I would reay like having some sort of clubs/guilds where people can interact more with each other. Maybe have tournaments. They can do the cashers and F2P seperatly so no harm gets done