Finally sucked it up and replaced our worn out water pressure regulator. Installed a shut off valve as well so I don't have to shut the water off at the meter every time.
The old copper with globs of solder is not mine. Whoever installed the water lines when this house was built should not been allowed near any tools, ever.
Case in point:
Nice job, and neatly done too! That last picture with the corrosion I'd be worried about. I had similar corrosion that became a seeping leak. (Maybe you already know but apparently such corrosion is caused when rosin flux is not adequately cleaned off.) My leak was in place that would have been very difficult to solder in so I invested in a hydraulic Propress tool. It worked really well.
Thanks! I've already found a pinhole or two that I've had to repair. Long term, all the plumbing and electric needs to be replaced. Thankfully most of it is pretty accessible.