Crazy, crazy world out there. It looks like I may get a green flag to have my company, Geodesic GraFX, on the community page at getrailo.org. I wouldn't be hosting today without a great open source product like Railo, and I'm flattered to be given a chance to have my name out there as a recommended host.
* I've used Eclipse and the various plugins for a good long time before CFBuilder was around.
* CFBuilder is not free. Yes, it has a "lite" version, but then you lose all the enterprise level stuff.
* I've never used RDS features.
If you were to install CFBuilder, you could skip the Aptana + CFEclipse step (since it's basically in there), but the other subclipse plugin would still apply.