You placed a lot of points in the post you made, and I agree with it - a simple implementation as such would be really helpful. To be honest, it is true that our only way to find out the enemy's level is through their poses. But in all honesty, as a new player myself that has only been here for probably a month, these poses really do mean nothing. Like, as I'm climbing up in PvP, when I see a new enemy I honestly don't know whether they're strong or not because I don't know them, much less their poses! The only time it matters is when I'm fighting the 'basic' guys/girls we receive from finishing the storyline.
I believe, as you have elaborated fully, Dunric, that it would be much more efficient and easier (for the noobs) to use stars instead and levels. That way we have an even more concise insight of the enemy's "harem power" when PvP. In addition to that, it would also allow us to view the girls/guys in our favorite positions.