Your wife is brilliant. 'Practicing for retirement.' You have to admit it's nice living where all the ranges and hubbub are far away though! That's my opinion on that matter!
I fixed the slumping of the Lee pots by wedging a rod vertically under the pot and base, back where it wouldn't interfere with the mold while casting. Out to the edge where it is stiff. The bottom cover is real thin and will dent severely if any pressure is put on it. If you want to stop the rusting of the heating coil, tip the pot sideways and run a little oil around it after shutting it down, and while it is still warm. That will stop the rust while in storage, and smoke like Mt St Helens when you light it up the next time though. But, it won't stop the oxidation from running red hot like it does most of the time.
About the melt being hottest at the bottom. - You'll find that a cold ingot is heavier than the hot metal and drops to the bottom like a rock in water, chilling the lead you would like to have run out the spout. If an ingot is well heated before putting into the pot, or, if one holds it with channel locks, up at the top of the melt, until it melts, temperature at the bottom of the melt will be far less effected.
Some years ago, I built ingot molds out of steel angle, 2X2 as I recall, and about 16 inches long. When I filled them, I'd insert a wire loop at one end before the lead hardened. A heavy paper clip works fine. I would hang these from a hook, with cable over a pully, terminateing in a chain coming back down. I could hook the chain on a row of screws in my pot vent shroud to raise and lower the ingot. By hanging the ingot so it only went into the melt an inch or so, it would melt off without slowing my casting. Then after it melted till there was an air space between it and my melt, the ingot end would be good and hot, so I could lower it enough to raise the pot level to the top. The ingot would melt off but never run the pot over, keeping it topped off for as long as I wanted to cast. I was able to cast 1600, 300 grain bullets an hour usin the RCBS promelt and no additional heat. The longest uninterupted run I made was 4 hours as I recall. About 6,400 bullets in one run. That's a LOT of lead for a melter to liquify in that short a time! I rigged up a melter that rendered down a couple hundered pounds of ww at a time to make the ingots, and had a line of ingot molds, so that part of the task went relitively quickly.
If you want to make similar ingot molds, here is the trick.
I used a large horizontal bandsaw to cut the angle. They type saw used in most steel fabricating shops. Tilt one end of the angle up a bit, with both legs down on the saw bed, so, with the cut starting at the point of the angle, the legs will be a little bit longer than the tip. This makes a draft angle to the ingot comes out easy. Knock off any burrs so the cut is flat, then lay them on a work table with legs down. Use a piece of flat steel that is a little wider than the height of the angle being used, as it lays on the work table, and cut ends about 5 or 6 inches long. Center them roughly on the angle, hold them snugly against the cut end of the angle and tack with and electric arc welder. Tap the end down tightly if there is any space showing, then weld on the outside only. There will be such a fine crack where the end meets the angle trough, when you turn the mold over, that no lead will get into it. Ingots will fall out easily as soon as they are chilled enough that they don't break when you dump them. It is easy and inexpensive to make up enough of such molds, making them as long as you want the ingots to be, that one can pour out 1 or 2 hundred pounds of lead in a few minutes, by cycling them soon as they solidify.
If you don't want to mess with the hanging ingots trick I used, keep your ingot cross section smaller, like maybe one square inch cross section, and just stir time in like a rod. I expect mine had a cross section of 2 square inches or more, as they were nearly 3 inches wide when I filled the two inch angle to capacity.
