Just used this yesterday so figured I'd help. For the combo trophies, I was able to pop 2 of the 3 using the combo save. I couldn't get the last one to pop with the combo save, but it would with the 5 million zeni save. Had to do 2 combos to make it pop. For all the arcade trophies, you have to do them yourself there's no way to save midway through. I used the 5 million zeni save for all the online trophies too. Just fight once in each mode (Ranked, Casual, Arena) and all the trophies for the respective mode will pop, along with the BP one.
Ok friend I followed the instructions and got all the mentioned trophies but I can't get the android 21 and talkative trophy... these 2 trophies are part of the story... what do you mean by BP