Another way to aerate is to simply pour your cooled wort into your fermentation vessel and then pitch your yeast (so be ready to pitch your yeast right after pouring into the fermenter). That's all I do any more, and yeast activity always starts on time. Pouring even my 5 gallon batches...
You should be fine, I've been brewing rural with well water, high iron (simple filter system) in the Oregon high desert for a couple years, and the batches taste great (similar to commercial brews), so you should have no problem with the water or altitude. Also on septic, I always dump...
Like others have said, milling your own will help... For what it's worth, I don't have an Anvil Foundary, but I do have a Brewzilla 3.1.1 and I get my milled grains exclusively from Morebeer, and I pretty much always hit my OG because I confirmed that my mash efficiency is around 62%. That is...
Looks like no water in the airlock, and the stopper was not tight enough... the batch should still ferment, but push the stopper in tighter in the catboy, and pop the top off the airlock, add a little water to the max water line in the airlock, and place the top on the airlock; that should fix it