Is it possible to take off the fuel injectors to have them cleaned, rather than just trying to run cleaner through the gasline? If so, what are the "gotchas" when doing this? This is the 3.5 V6 engine.

In general yes, there are places that will clean and match your injectors, GOOGLE and you'll find'em.

Down side, you'll be down while its being done, you could damage them removing/installing.

Get new O-rings for the re-install.