Plumbing – Replumb sillcocks to increase outdoor pressure

I will usually feed the home with 1" but then drop down to 3/4" and have not had problems with flow. Most of the plumbing to your sinks is 1/2" and the orifices in the faucets are much smaller so even with the kitchen sink and a bathroom or 2 having there valves open you should not see much of a change in flow at all with 3/4". The one place that will affect the pressure is hose bibs or outside faucets these have much larger passageways in the valve than sinks do. Already mentioned the flow restrictors in shower heads, these are taken out at my house before even installing them. Not long ago I found a flow restrictor in a bath faucet, don't know how filling a tub slower would save water but that came out also. With my shower head restrictions remove our guests mention how nice our pressure is. 60 should be a big improvement over 50 but look at your restrictor if you have any build up issues like lime, scale or rust the head may need a good cleaning that and removing the showerhead restrictor will probably provide the results you want.

I doubt you need the second 90 (#3) - PEX is bendable at large radius, and if you work with that, you avoid fittings that may have freeze damage (PEX itself does not mind freezing.)

If you think of it as if it was rigid pipe, you end up with a lot of fittings. If you work with its strengths, you can avoid many of those fittings, but you don't get tidy pipe-like runs.

I would be concerned with complete drainage ("slightly angled down while running under floor joists" may work for properly hung rigid pipe - pex is not rigid pipe.)