A well maintained cricket colony shouldn't stink. If you open it and stick your head in, there's a smell, but otherwise for even 3 or 4 hundred crickets it shouldn't be an issue (your nose may vary though). Even if you don't plan to breed them, give this article a read Frog Forum - Culturing Crickets - Care and Breeding of the Common House Cricket, it can help you get set up to buy a few weeks worth at a time which also lets the tiny ones do some growing before feeding. Feeding real small crickets is fine though, it just takes more.

Wax worms are high in fat and low in nutrition, and fine treats just not staples. Same use for mealworms, and they're worth having a tub around even if used very sparingly as they are just so easy to keep. Your frog being wild caught, there should be no problem feeding some wild caught food if you have a chemical free area to collect from. Sow bugs and earth worms are good choices for more variety. You can buy earthworms as well, but you'll probably have to chop the usual store bought ones up for a frog of your guys size. Earthworms are high in protein and excellent nutritionally if your frog is interested in them (not all are).

As you've noticed, they like to be high, so try to provide some cover up high. If you're new to plants, you can start with Pothos (devil's ivy). It's widely available, will grow up glass, and is hard to kill. Just be sure to rinse the plant off carefully and repot in frog friendly dirt like cocofibre (or put a plant&frog friendly substrate in your tank instead of paper towel and plant directly). Or you can use fake plastic plants, definitely not my preference but it would be better than nothing up high. More the merrier, it will feel safer if it knows there are several hiding spots in the vicinity. I'm sure you're aware that a bigger, and specifically taller tank, would be a good idea for the long term.

As to the rear lifting- it may be peeing. Is their some turbulence behind him? My grays sometimes pee in the pool, and it looks kinda like you describe.

And, you're welcome