1. I think you mean the following. Just enjoying sensual pleasures is not bad in the sense that cannot lead to rebirths in the apayas. If one engages in immoral deeds (like stealing, killing, rape, etc.) in seeking sensual pleasures, those are papa kamma that will lead to such bad rebirths.
– However, as long as one has cravings for sensual pleasures, one will be reborn in the kama loka. That is from Paticca Samuppada: Rebirths in kama loka are inevitable if one cultivates corresponding abhisankhara (i.e., think, speak, and engage in actions SEEKING sensual pleasures).
2. This is exactly what I discussed in the latter part of #1 above.
– As long as one has cravings for sensual pleasures, one will be bound to the kama loka.
– The danger in remaining in the kama loka is that one could be tempted to do immoral deeds if the arammana is strong enough. For example, there are many people who will not take bribes. However, if the bribe is large enough, even they could be tempted.
– That is the difference between a Sotapanna and an average human. A Sotapanna will not be tempted to engage in any apayagami actions, no matter how strong the arammana is.
3. That is exactly right. It is better to say, “Trying to maximize sensual pleasures with minimal suffering is thinking like fish who tries to eat a worm from a hook. The fish does that because it cannot figure out (i.e., “see” with wisdom) there is a hook hidden under that tasty worm.”
– In the same way, one who has not reached at least the Sotapanna Anugami stage is unable to “see” with wisdom the bad consequences of craving sensual pleasures.
– So, there is a big difference between experiencing sensual pleasures and craving them. Of course, if one is constantly immersed in sensual pleasures, it is hard to even think about the bad consequences of them.