For Romance EXP, yeah, a massive amount of Rice Cakes are needed in a single day, and some people are willing to spend buckets of money for daily progress/mission completions. Some days, if you're lucky, you may only need less than a thousand. Other days may have multiple people playing up to 1500. You can slightly boost your EXP with the chance of failing the Minigame/Enemy Appearance Checkpoints over and over, and that's really it.
As for Tapjoy, in one of the other games, Ninja Love, there had been similar reports that NTT Solmare addressed recently. Though it's not necessarily related.