I have revised my drain/vent sketch as shown. Again, although I'm in an area not subject to code, I would appreciate a plumber's
evaluation to make sure that I'm not making any major mistakes.
Sink #1 is the kitchen sink; #2 is the bath sink.
Of course, the bath sink, commode and tub are in the same room;
they're shown like they are on the sketch just for clarity in how the piping is run.
One thing I'm not sure of is the drain for the kitchen sink. I've read that 42" is the max horz. run before going down and the distance
that I need it to run 66". The dark 2" line down from the kitchen sink is another way that I could run the drain, but I'm
not sure if that is too much drop and might empty the trap when a sinkful of water is drained.