Correct on the first part and about the culture it's always hard to say since personnel can turn over very quickly. YMMV
Surprisingly great while I was there. Nothing but good things to say about the ATM and FacRep. Again, could be new people so YMMV.
Yes, also KIWA is a NATCA facility. Not sure of the exact amount but its around 1.7% or something like that.
Personal opinion/experience:
Great facility if you like busy traffic. FCT's are underpaid as a whole; make no mistake you will earn your paycheck here. The FAA and local government are currently building a new tower at this location with construction set to complete in late 2022. I've only ever heard rumors of FCTs turning into FAA controlled airports, but if there was a prime candidate for it to happen, it would be KIWA. Quality of life outside of work is amazing here, tons of stuff to do in the immediate area and plenty of things to spend your hard earned money on... Housing in Phoenix metro is getting expensive; technically the tower is in Mesa, but most guys live in Gilbert/Tempe/other happening areas of town (generalizing), those who like a more quiet life live towards Queen Creek area (generalizing).. All very good locations, choose according to your lifestyle.
Overall: 8/10 would recommend. DO NOT go here if you want an easy cert or if you can't handle serious traffic volume. FWIW, I left to chase money overseas.