Erick,
The only written paperwork available for the skimmer at this time is the assembly diagram. But, I can help you set it up, no problem.
1. You can use any pump you want to feed the skimmer. The only requirements for the pump is that it can push 1.5-2 times the entire water volume of your system but cannot exceed 700GPH. Say you have a 300 gallon tank. That means you need a pump that can push within the range of 450-600GPH. If you have a 400 gallon system, then you need a pump that can push between 600-700gph. Not 800gph because the skimmer can only handle 700gph max. What size system do you have?
2. See above
3. The drain line is for those people that do not want to be cleaning their collection cups once or twice a day. The drain line allows you to collect the skimmate in a separate and larger container. It also allows you to use some type of automatic shut off system so that if the skimmer starts to overflow for x reason, the automatic shutoff system can turn off the skimmer immediately if the collection container is full.
4. The skimmer works on gravity to expel the water from it's body back to the sump. The outflow plumbing is made large enough not to create a bottle neck or back pressure that could make the skimmer fill out faster than it can drain itself. The output pipes should always be horizontally or going down. There should never be going up over something and then down. That would create back flow and would not allow the skimmer to drain correctly. If your skimmer output is going up and over the sump wall, then you need to raise the skimmer so that the output plumbing is horizontal or downward at all times. Also, the bottom most part of the skimmer should always be higher than the water level of the sump during a power outrage. If not, the water may overflow out of your system though the skimmer and cause a flooding.
5. I am sorry about it but all that was provided to us from Reef Octopus was the assembly diagram. I will be more than happy to answer any questions you have. You can call us at 985-781-9078 and select Reef Octopus support.
Kind regards,