caliper with no pads and a badly damaged rotor, how to remove the damaged brake rotor?

HMM, the edit window is set to 2 hours I believe. I know it is for me. Gravity bleeding works well unless you let in air. My process of replacing a caliper is to start with the master full, then put a bar between the seat and brake pedal to hold the pedal down just enough to close the transfer ports in the master cylinder. That usually prevents the fluid from leaking down when the caliper is removed. As for the master, if it's a plastic unit, I use a turkey baster to remove as much fluid as possible, then use a rag on a stick or hemostat to wipe out the interior. If it's really dirty you can lightly dampen it with some brake kleen. Then refill with fresh fluid. I usually bleed in sequence every time. In theory you don't need to but if you let any air in, that could go anywhere. A dirty trick in that case is to pop the caliper free, put a pusher on it and push the piston back it to push the fluid in reverse so it takes the air with it into the reservoir. For that I also remove some fluid first. Then fill and install the caliper back into place and gently push the pedal to set the pads back into place, while watching the fluid level. If in doubt I'll use a scan tool to activate the ABS while using a pressure bleeder. Even then there are a couple models that still have very soft brakes, even with everything perfect.

Thanks, Steve. That helped a lot, especially liked your "dirty trick" on, in effect, reverse-flushing the caliper. Your point about cleaning the master cylinder reservoir with a Brake-Kleen-dampened rag, after removing just enough fluid, should clear a small viewing window.

Pedal
Lo and behold, the pedal seemed much better this afternoon when tested, to be sure I needed to pull off the wheel and re-bleed. I'll drive more carefully than usual the next few days, and any remaining air pocket should reveal itself.

Next, the Rear Brake Drums
All the old parts will be removed, replaced with new drums, shoes and cylinders. Although I have done the procedure with several cars, it always seems like the first time, until I recall the familiar spring removal order, etc.

Electric Impact Wrench
Have reached the point an electric impact wrench seems desirable. That would help me set the torque more reliably and consistently on the wheel lug nuts, which is my only use for it., Yes, I am probably over-cautious about using such a tool on the lower-torque-value bolts, and prefer to operate by the feel of a bolt as it nears its assigned torque value. If I were a professional mechanic, where time-is-money, using an impact wrench everywhere possible would be the only way to operate. When and if the day comes, I want a more "delicate" electric wrench, do you have a recommendation for brand or type of wrench to use to loosen and accurately reset torque on smaller bolts, like the manifold gasket?

Go grab your cell phone. Remove tire, knock the drum free and remove it stop- take a picture up close of the leading shoe and trailing shoe and the spring and adjuster locations.
Now when you put it back together you have a guide for your car. Do the same on the other side. Be sure to clean and lube the adjusters (yes even the new ones, they rarely have good lube on them)
If the brakes seem better than the air might have been trapped just below the master cylinder.

Oh, yes, cellphone photos can save the day. Long before most people used a cellphone to document their auto repair work, I had discovered how important a good reference photo can be. The best part is today's cellphones have really good closeup lenses and reasonably fast shutter speeds, so a well-lighted view of almost anything is possible.

Pedal Update
There is still some air in the left front, so that is my next project-- even before the rear brakes.

Electric Impact Wrench
After reviewing cost of a complete electric wrench-- wrench motor, charger, battery and impact socket set-- I realized I am into another, relatively expensive gadget that is a labor-saver, but not necessary for my limited amount of auto work. For removing and reapplying lug nuts, a breaker bar is completely acceptable.

Bleeder Screw
Have run across some articles recommending that if I ever find a caliper bleeder screw frozen, I should consider another bleeding method, rather than strip the valve. That complicates the bleeding process, but the POV has value. In my history, one of my cars had a bleeder screw stripped out by a careless brake mechanic. What other method, if any is available, could I use? You mention you prefer a power bleeder.

Where I am bleeder valves last about 2 years. The increase the chances they come off I scrub around the with a wire brush, then heat them with a torch just a bit. Then use a 6 point socket on them. I have all the tools myself because they save time. For breaking lug nuts loose I've used 24 or longer bars if the air isn't handy. The power bleeder I use is air powered, but they do make them based on pump style garden sprayers that work just fine.

These are the style I mean:

https://www.motiveproducts.com/collections/brake-bleeder-kits

A clever person could easily make one if they looked at some of the YouTube videos.

Thanks, Steve, good advice. I had to resort to a six-point socket to loosen the last one, because the "C"-shaped 10mm wrench was beginning to slip, and I did not want to round the bleeder valve.
Nothing cleans an encrusted thread like even 30-seconds with a (fine) wire brush.