Hi buffalobill. Thanks for the suggestions. I am thinking of calling a plumber, if only for advice. The interior plumbing is mostly repiped. I will be terminating in a remaining galvanized section, soon to be replaced.
You are correct, the original installation used 1/2" running to the two bathrooms, and there was some advice to go with 1/2" . I installed one section of 1/2" to the washer with many elbows, and the flow rate was awesome. Also, both bathrooms had sufficient flow with the original
1/2". Code in my area allows 1/2". But Hemp's book (awesome!) says use 3/4", so thats what I went with.
As for winterizing, this is a year-around warm area, and it is even allowed by code to run copper pipe along an outside wall. There is no freeze protection anywhere, and the local big box stores do not even sell freezeproof garden hose valves. Vacuum breakers are also not spec'ed, so most stores do not sell them.
I will fill lots of pots full of water. The main shutoff at the street works fine. I had to use it when I broke the PVC main a couple of years ago while replacing a sprinkler gate valve connected to the PVC pipe. It was kind of brittle. That's why I am afraid of the same thing happening here. But there is one difference. The PVC in the current case has a MIP adapter that I can easily get a wrench on. This should relieve a lot of stress on the incoming pipe as I am removing it. But there is little room for error.
Thanks, Eric