There are several advantages to ouside tap, but make sure that the county allows you to tie inside the meter pit. Many counties only allow outside pit. You will gain a bit of flow and pressure, but normally not that much to make difference. As long as you tie in before any regulator on your line in basement (tie in immediately after house shut off) then you will not sacrifice and gallons or pressure. the distance form meter to house is not enouh to make difference unless you have kink in copper ...
Please call me for parts to the Rainbird valves. Is the diaphram shutting? We can help oyu find parts.
Just tape the openings in the piupe after removing the PVB. Question, though... 3/4" is rarely used and only allows 8-10 gpm through. Curious why this was chosen as size pipe.
If you have flow problems, there are several reasons. I can discuss this further, and quickly resolve the issue for you. i like to 'wind down' in the evenings, so please call our offices at 513-779-6850. no charge, just love to chat about the business. Ask for Doug