holy cow, the whole set up looks like a first timer DIY job, who the heck would run the water 2ft next to the electrical panel? does that even meet code? The pipe looks undersized too, how is your water pressure and supply? I doubt that you'd get 5-6gpm. The panel is grounded to the water pipe too? If you add a water softener, you will most likely use a plastic bypass valve, and anything that grounded to the pipe after the water softener would not be grounded anymore, something to watch out for. you are in for a world of hurt.
What are you talking about? Electrical panels are (were?) commonly grounded to the water system, because the water system goes underground outdoors. It has nothing to do with the rest of the water system in the house. If you wanted to, you could ground it right where it came into the house, then switch everything else over to CPVC or Pex, and it would still serve the exact same purpose. If you're worried about things grounded *after* the softener, and you put a plastic valve in there (why? It's copper pipe, and the valve is already there. It'd be just as simple and cheaper to replace it with a like valve) you'd just need a jumper across the connection.
You could probably just buy the same valve (looks like a very common valve), shut the water off, take that valve apart, and install the new "guts" from a new valve. Installation of the water softener with that setup should take half an hour for a decent plumber, maybe 2 hours for an amateur. If you hire a professional, just tell him you've got a bad/sticking bypass valve & want to install the softener, just don't feel like doing it yourself, in case there are any problems. I haven't shopped for water softeners in about 8 years, but it seems that back then, all of the ones I looked at had a bypass built in. Thus, if that bypass valve is stuck closed, it shouldn't even be an issue.