No change in the filtration since day 1. Yes, still using the SWC300 and love it.
I have added some tunzes for flow. A 6255 on the right, and a 6155 on the left (next to the original 3200gph Koralia). But I really love the 6255, so I may replace the 6155 down the road.
I change 80g about once every 6 weeks. My nitrates are probably pretty high. I need to get some chaeto in the fuge.
Not sure what you mean by "access to water"... but I don't do anything in the actual room that has the tank. I pump everything in and out from either the bathroom or the kitchen.