I view only things that are actually used to determine the seeding as relevant. You can view things however you want, do not care.
One difference between RPI and NET, is that RPI is all about percentages (win percentage). NET is not based on percentages. There are 4 quadrants. I do not know exactly what the break down for each quadrant is at the moment (it is on ncaa.com somerwhere) but the first quadrant would be for teams ranked 1 through some number, second quadrant after that up to some number, so forth). The more wins you have against teams in the first quadrant is good, the more losses against teams in the fourth quadrant is very bad). Outside of that, there isn't enough info exactly how it is determined. It is not as transparent as the formula on how RPI is calculated.
www.collegerpi.com documented how RPI was calculated and is one of the best sites (if not the best) for RPI rankings.
Conferences are not ranked. Only individual teams are. But, there are sites that rank conferences based on the average ranking of each team in each conference.