Identification of Thru-hull drains...and low phosphate soap options

Killing two birds here, but related thoughts to do with draining overboard. Being new to a cruiser I will admit it's been an education. Please don't laugh, but I always naively assumed that the only water being used and discharged on a boat came from the freshwater tank, and drained into the waste tank, with the exception of bilge pumps of course. Who knew that the head used a seacock/water intake? And it, of course, pumps into the wast tank. Everything else uses freshwater, but drains overboard....now I know!

Noticed on my 2000 FV270 that there are a couple of extra thru hull drains that I can't think of a reason for. The two chrome one's at either side of the bow I assume are for the anchor locker?
There is one on the port side under the aft porthole, I assume for the head sink?
There are 4 on the starboard side, three on a lateral line about a foot off the waterline and one down lower just above the waterline. 1 for galley sink, 1 for shower sump drain, 1 maybe for mid-ship bilge pump? And 1 I can't think of...or is this the aft bilge pump drain? 

And the second part of that...with dish, shower and wash water draining overboard, does anyone have recommendations for good low-phosphate soap/shampoo/dish detergent options?
Phosphate (and the elimination of it) has been a big focus on the lake, and all the marina's are pushing for low phosphate, or even the elimination of soap on board.