Bus ROW is essentially free, and the Everett bus lane shows that even exclusive ROW can be pretty cheap too.--paint, cones and a 30 minute DPW pass each rush hour. And stops can be dirt cheap too...A small shelter will do (SL & SLG are silly in their "architecturally distinctive" shelters...Two Standard shelters per stop would have done it).
I don't get the second point. Mine was that bus and land transit stops (mostly,) serve dense two-sided streets, and serve demand a full 360 degrees around a stop, while ferry stops are always half empty (no body lives or works in the 180 degree arc on the water side of any ferry dock--only on the land side)