plumbing layout questions

[dug]

I've been through some of this before here and as usual received good advice but I'd like to go over it once more before I pull the trigger and start drilling holes.

I may well change my mind again but as of now this is the plan, it is a branch system using pex tubing.

200 ft. 1 in. (pex) from well to house supply, buried 2 ft.
build insulated chase for the 2 ft. section where tubing leaves ground and enters house.
Shutoff valve inside
3/4 in. tubing run through insulated (2 by 10) joists, 2 inches below subfloor.
1/2 in. tubing through floor and into wall, terminating at brass drop ear elbow.



My main concerns are freezing and repairability. I was going to run all the tubing in the walls but I figured they wouldn't get much, if any more insulation value there than in the floor joists, and it would be an easier repair with less possible damage with them underneath. Of course I know I still have the tubing poking up into the wall also, but still less tear out if something goes wrong.

I was also thinking of building a chase along the base of the inside walls, which might be the best option of all but I'm not exactly sure how to go about it, especially around the shower.

My questions-

1) Does the above mentioned plan seem a solid and reasonable one?

2) Tubing sizes O.K.? Not sure if the 3/4 tubing is necessary but I have some I need to use.

3) Should I scrap this plan and go with inside plumbing chases?

4) Other?

[Native_NM]

If you think you might ever have a tankless hot water heater, 3/4" is almost mandatory to get the full benefit of it.  Do a Google search for more info.