tl;dr version: look for links and game titles in the text-wall below
As far as the action-oriented RPGs go, I dunno. Indie game devs don't do a lot of action RPGs. I think these days people have kinda high expectations for action RPGs, which tend to end up with a lot of visual work needing to be done. I guess that's why you don't see them often even with stuff like Unity running around. PORN action RPGs are going to be even rarer.
Wings of Roleda or whatever is one, but it's made in Wolf RPG and so the sprites are kinda small and the battle system's a little janky. The same dev has one or two others in the same vein. They're sprite games with some CG scenes and some in-battle porn, and the translations are of the bad-but-workable variety. A Japanese dev Luna Soft made something called "Magic & Slash" a while back. Not translated and not very interesting for me, personally. One or two of these guys' games are action RPGs, but they're not translated.
As far as dungeon-crawlers with turn-based combat, there's that Enlit3d game and Lewd Maze, off the top of my head. Both of those have a LOT of development time left, though, so don't be looking for any story there. The Japanese LOVED Wizardry, which is why I'm surprised I can't think of more H-games in that style. Funny enough, the Wings of Roleda dev (Waterspoon?) has one: Prizna, Princess of Puppets or something like that. It has a translated version and is a Wizardry-style crawler with turn-based combat.
Oh, wait! There's a game called something like Futaring by some Japanese dev like "Mofuland." Translated versions exist, there is porn in it, and it's a tactical RPG so there is some actual gameplay. Unlike Portals of Phereon, it's finished--come to think of it, PoP has porn and gameplay already, if you like tedious tactical RPGs.
I wouldn't be looking for story pretty much anywhere from a porn game that has actual gameplay. It's a "good porn/actual gameplay/meaningful story, pick two" situation. Heck, both the AAA guys and the indie devs have trouble with the gameplay+story combination. Putting a third requirement on top of that and restricting it to indie devs (who have the fewest resources) is pretty much asking for nothing much to come of it. Then on top of that there's the fact that the Japanese have a huge independent adult game development scene, but those games are usually unplayable without translation.
Honestly, your best bet is probably Oblivion and Skyrim with plugins. Still not much in the way of story, but at least it has the charm of variety. Oblivion had a HUGE adult modding community, but that was... what? Seven or ten years ago? Christ I'm old. Fallout 3 and New Vegas sorta did, too, if fantasy isn't really your thing. Skyrim's adult mod scene I can't speak to. Be prepared to do a lot of work, though, if you want to run a bunch of plugins together and keep stuff from breaking. It's usually pretty trivial to get everyone wearing skimpy armor, at least. But plugin authors for all of those games have done some ridiculously impressive work, considering that pretty much all of them work for no money. Then again they have the base game to build on, but then again again the OBSE guy and his cohorts have made those games do things they really weren't built to do.
EDIT: Oblivion was released in 2006, and I still think of it as a modern game. Man.
OH! That reminds me. Neverwinter Nights (and maybe NWN2) have some adult plugins that I understand may have some porn. Depending on how desperate you are, you could try digging those up.
