Yeah, Phoenix heat will do that. My old drill battery basically turned into a paperweight after one summer out there.

Totally agree with @tyler_white42, we switched for that exact reason and the clear reports changed everything.

Yeah, those lime-heavy mixes can get grabby fast, especially if the bricks are thirsty or it's a warm day. I keep a spray bottle with clean water and just mist the mortar board and the bricks themselves a little as I go. Not enough to mess with the mix, just enough to slow down that suction. Also, mix smaller batches so you're not fighting the clock on the whole load.

Yeah the zest with garlic thing is a real trap. @gonzalez.wesley i get that, juice is safer but zest can work if you treat it like a garnish at the end.

Stick with the thinset every time. That pre-mixed stuff is such a trap. I've had good luck with Mapei's stuff from the big box store.