Theoretically, all RPGs are turn based unless you're doing some really crazy stuff with multi-threading, as technically its hard to have everything update synchronously. You just have very fast, automatically switching turns.
In other words if you played Oblivion on a REALLY crappy pc you'd have gobs of time to think in between actions ;)
useless second screen, useless stylus features in several games
That's the software guys' fault. The stylus is logically a mouse analog and the second screen is a logical "Mouse analog on bottom, important menu/stats/whatever stuff up here" thing. It's not Nintendo's fault the dev's don't know what they're doing with it.
In particular, something like ultima 7 would be REALLY good with two screens, as it could get cluttered with character sheets fast.
Puzzle Quest also used it in a really appropriate manner, and had shoulder buttons for swapping screens so you could use the stylus on either as necessary. Puzzle Quest is also made by someone with a background in PC game development, so...
What I'm saying is that it's like someone (Xerox) invented the mouse and all the software developers missed the point and made it some sort of really peculiar keyboard-esque thing where the letter you want to input is based on how exactly you wiggle the ball, and the mouse button was more like a shift key.
Styluses are for doing what you'd generally do with a mouse. If you have a simple and condensed interface and are mostly using keyed input, keyed input for the menu works best. If you have something more spread out, you need a clicky device. Game designers are just notoriously bad with interfaces, honestly (Although credit does have to be given to whoever came up with the Ring menu in SoM for inventing pretty much the only not-totally-obnoxious pie menu type thing *ever*).
It'll probably get better, though. Early PC games too a while to adopt the mouse for whatever reason, and were sort of goofy about it at first. Eventually they got it straightened out unless 'they' refers to someone affiliated with Gothic.
Which would work out nicely anyway with the DSi having dropped GBA support.
Yeah, what the hell. Part of the thing I love about the DS is how it makes GBA games look *fucking awesome*. But no. You don't want that. So have a crappy little camera instead. And some doubtlessly undersupported downloadable content thing that doesn't support homebrew*.
* Better solution. I'm pretty sure flashcarts themselves are legal as long as you're not screwing with the system, which should mean that they're fine for the DS at least. Even if they weren't, nintendo owns the right. So, sell official, easy to use flash carts and approve free, homebrew software to make sure it's not emulators, and sell your own downloadable stuff for the flashcarts on the side. This way, you help the homebrew guys, still sell your own downloadable content, and you also get money for selling flashcarts, which definitely sell, instead of having to bank on people wanting a crappy camera and no GBA support.