For me personally the recording aspect is easy.
I had a weird stroke of luck actually, if you check my topic you'll see I just uploaded 2 coasters at the same time, now although I presented them together they were recorded about a week apart.
Now, since I have had my new PC I have completed about 5 or so coasters and recording for some reason has been really really slow, to the point where the POV for Rush took about 2 hours.
Now after I did that I had a break before I recorded the other one and I got Train Simulator 2013 (because I'm cool like that) one of the graphically most demanding games, whilst installing the game, it did some sort of optimization to my graphics card, the game runs beautifully and stupidly quickly.
So going back to RCT 3 I recorded the POV for Razor in literally 15 minutes, infact I shot the whole video in one session, something I have never been able to do.
Moral of the story is, get yourself Train Simulator
No but seriously though, I too swear by the in-game recording method as opposed to fraps, yes it takes for ever but there's things you can do, for example whilst recording the POV, just set it up and leave it to do it's own thing whilst doing your normal routine.
I set it up then take the dog out for a walk or something or have dinner, it will be done before you know it. Same with the uploading to YouTube, just pop the Xbox on for a bit or something, key is it will take half the time if you just set it up and forget about it for a while.
As far as putting the clips together for the video, for me personally this is the quickest process, I have all clips I want to use in it's own folder so I don't have to find them in the RCT 3 folder and I normally know what music I want to use, which makes putting the video together easy as I put it together to match the music if you know what I mean?
In a nutshell
I recommend using the in game recording and just engage yourself with something else whilst doing it
Build your video around your music (carefully chosen of course) and upload straight to YouTube.