I just got a Chromega drum w/ a chromega motor base. I have a few questions:

1.)
I see that the base I have does not switch the way it rotates. it only goes one direction. Would I want to switch my drum during development so that it rotates the other way for more even agitation? or should this not matter?

2.)
I plan to use this for 4x5 and 8x10 film. I know how to set it up for 4x5, but if I'm doing 8x10 I'm unsure; It has 3 plastic removable separators that slide into slots, how many do I want in if I am doing a sheet of 8x10?

3.) How much chemistry should I use?