I'm not sure how you busted the bib off, but hilarity indeed. Every hose bib I'm seeing on new construction is on pex, crimped. Absolutely no way to remove without cutting the wall, no screw on fitting, no extra shutoff. No access panel either. They're usually run into an inside wall to give them the clearance. It would be so easy to put in an access panel... I guess in theory you can replace the innards of a frost-free. I am so glad when I replaced both of my taps with frost-free I used screw-on fittings, and left them accessible. One, I used a 1/4 turn ceramic, the other one's conventional so it will need replacing eventually, but my neighbour gave it to me, so I couldn't really say no. :) Twisting pex like that would be so much worse.

wow this made my day ... After finding are home flooded with sewer water and then getting every thing ripped out and redone ,,, after we started to put things back in we found a wet spot on the new carpet in the office .... so had the guys remove the new drywall from the floor up to about 3 feet thinking they hit a pipe with a nail , or a screw ... nope was the the main copper pipe drain for upstairs bathroom ,, cut out higher and found the leak in a elbow joint ,, in a very hard place to fix ,,,, so went out and got the ep-200 epoxy putty ,,, cleaned up the joint really good then applied the epoxy .... been 2 days and still holding ... so this gives me hope ... until i can get it fixed ..

lazypup's in the ballpark but I think his long discourse on cavitation is more tailored to an extreme version you'd see in a hot water system. Cavitation occurs at a microscopic level. It happens at points in the pump volute and on the impeller where low pressure occurs (the trailing edge of the impeller is the best example). If the suction head required by the pump to operate is greater than what's available due to suction line throttling or friction losses, the low pressure becomes low enough to cause water to vaporize. It's technically "steam" but not like you think b/c it can happen even at room temperature. This can be exacerbated by pumping a hot fluid b/c it has a higher vapor pressure (i.e. it 'boils' easier). Your pump can be sitting there pumping water pretty much normally and still be cavitating. Lazypup's description makes it sound like you suddenly get a pump full of steam, but that's not the case. The bubbles that are formed by cavitation immediately collapse back on themselves and that's what causes the pump's parts to erode, since the bubbles occur at surfaces in the pump. It sounds like you're pumping marbles. Lazypup's description sounds more like a pump that's air binding. For hot water, it can be an extreme version of cavitation. But what he describes sounds more to me like a situation where the pump is depending on the pumped fluid for some of its lubrication/cooling. If the fluid isn't there, then the pump can quickly overheat.

There are all kinds of variables here. Is this above a crawlspace? A basement? Can you get under there to work from below? What kind of flooring are you putting back down? Is your current subfloor in good enough shape that it doesn't need any structural help from whatever you are putting over it? At the very LEAST I'd cut the copper right below those shutoff valves and put new modern shutoff valves and supply lines to the sink and dishwasher. I'd never recommend enclosing a "push-to-connect" coupling in a wall even though you technically can now by code(I just don't trust them that much), but you wouldn't have much trouble just pushing a couple Sharkbite valves on the cutoff copper that are already threaded for your supply lines. You'll have to get a "T" and shutoff for your dishwasher hookup I see there as well. Also I see you have a big old copper drain line there which tells me almost certainly you don't have proper venting based purely on the age of the home. If you don't want to tear open walls and do attic work to vent to the roof, you can put a loop vent in like they do on a kitchen island(assuming you have at least one location in the house to tie to) Don't miss this opportunity while you have everything apart. You want your kitchen sink vented for sure. Plumbing isn't super hard but it is super hard to get all the details right. If this all sounds complicated I'd maybe get a plumber in to rough everything in for you.