I "believe" you will have to have a fitting welded on the pan. I'm not sure it's thick enough to simply tap. But I could be wrong.. if it works, it works. As for the radiator fitment, I think that you will probably have to go with a Civic half radiator. They're like $80-90 at Autozone.
The boost controller shouldn't be absolutely necessary. But I guess you could throw one on later down the road. I'm not real sure 380cc injectors are enough to make 230-250hp. And i'm not sure you need to wire up resistors for injectors that small anyways. I haven't heard mention of exhaust. That should be on your list. 3" or so.
Just buy an O2 sensor bung and use that for your oil return. Of course that means drilling the pan and welding... but you shouldn't have any worries if you go that route.
I think 380cc injectors may get pushed to their limits. I ran 450cc injectors and they were causing me to lean out at higher RPMs on 12psi. You will probably be a lot safer with larger injectors. Just because you have big injectors doesn't mean you have to use them to their full potential with your tune. And the resistor box will be needed to run the DSM injectors so you are set there.
So far you look in good shape though. But I'm sure when you do the build you will find all those odds and end pieces that you didn't think of. Like clamps for all your piping, vacuum lines, and even fittings to T off the vacuum lines.