[mark]

Did you get the leak fixed? could be the ferrel ring is facing the wrong way.

1.green beads the di part of the ro/di
2.concern I would have with the vampire valve is know at least with mine, with the valve full open there's still some restriction and I've had to replace mine once as well as the rubber swelled . The waste should be unrestricted.
3.the valve is a flow restrictor/flushing valve (the unit needs some back pressure to force water through the membrane), normally the handle is 90° the the line for operation, turn open to clean the membrane
4.running my Aquasafe with the standard filters, seems to work okay
5. sorry if confused that one. You run the valve full open. What I was meaning cold water decreases the efficiency of the unit. Feeding the unit warm water would be better be not easily done, don't connect to the hot line as will wreck the membrane. Read on the Aquasafe site a while back the the gpd rating is at something like 77° and a certain PSI and for every degree below, down rate the unit by ~1.6% (believe these where the numbers)