The early rooms will remain short, if they were long, it'd get boring; they're supposed to be the easiest ones, really.
And yes, you are supposed to dodge stuff...
Ah, there was a time when health-regen wasn't even a thing... never happened in games, way back when. Got hit too many times without finding healing items, and bam, you were dead. Nowadays... ugh. I've never liked regen systems. To me they're fixes for something that was never broken, and an unnecessary bit of handholding at the same time.
THIS game though is meant to murd- uh, I mean, challenge the player properly. One thing I didn't like with some other games in this genre was that honestly they were just too easy. Like, I love Isaac, but even on Hard the game just isn't all that tough. It has no regen or anything like that (well, no, there's an item that does that, but it does it ridiculously slowly so I don't know why it bothers...) but it's still a pretty easy game. Others tend to be like that. So this game specifically isn't.
Not that there aren't issues though. I'm still doing some of the damn room renovations (that's a HUGE issue right now, and if you saw Managarmr's video in the Hard mode thread, well... he ran into more than a few broken rooms) and of course the whole player power progression thing is being worked on (not by me though, it's full of scary math).