The plan is to drain and remove the tank and fix the leak today and tomorrow, I'm slow due to rheumatoid arthritis. The new pump will arrive Tuesday.
On the P0442 this may not help, but maybe it will. It took me like 2 years to finally repair the issue on my daughters 2003 Monte Carlo. I smoke tested it time and time and time again and tested the sensors never finding an issue with the sensors. I found several very minor leaks or slightly loose fittings and repaired them and thought I had fixed it each time just to have it fail the evap self-test a few weeks or months later again. I had replaced every vacuum line, o-ring, the purge and vent valves, replaced seal on the tank pressure sensor. In the end I realized every time the CEL came on recently due to P0442 the tank pressure sensor had popped out a little which tore the seal each time. Previously I had swapped the seal and that seemed good. This time I swapped the tank pressure sensor and it finally resolved it. My theory is the tank pressure would get too high due to sensor intermittently failing and the sensor is just held in by the seal so it unseats itself. This sensor had been tested good several times.
I'm kinda lucky that we have 2 of these Monte Carlo's as daily drivers so parts swaps are easy for testing when I get stumped, but I also have tons of spare parts for them after 1 was totaled and another was bought for parts of course stripped everything I could save from both.
Anyway, it may be something that for some reason you're over looking like I was.