Well, as I said, RGBA is only available on hero. Tiers go: initiate - warrior - champion - hero. Perhaps I missed your other questions about it? I felt as if the RGBA situation was pretty thoroughly addressed...
Hilts vary in size, but as a general rule SF sabers run on the small size of the spectrum. Apprentice sabets are smaller than elite sabers. Most size measurements can be found on the sabers listings but not all.. on average the length is around 10-12 inches for most sabers. Some with claws are longer. Blade length, you have your choice between. 26, 32, and 37in. It's mostly personal preference.
You should technically never have to open and fiddle with the internals of your saber. Doing so actually will void your warranty. Do so only at your own risk, and with some experience, preferably.
Wrench size is 5/64" for the blade and led retention screws. These 8-32 screws hold the blade and led in place in the hilt and are accessible on the external hilt of the saber. Only mess with the led screw if you have quick connects on your saber, otherwise trying to remove the led will most likely result in a broken wire.
If you have more questions, being specific with what you're asking helps. General questions it's hard to know exactly what you're asking, and can lead to some frustration in not getting what you're looking for.