I had a 2018 CX-5 and it was the first year of cylinder deactivation. There were some problems that were documented on this forum. Everything OK for me. I didn't even think about it when I bought my 2023. I feel the engine is solid. It's been a long time since I have read about any deactivation...
While an alternator may be dumb, they are controlled by some pretty smart electronics. The days of the little black box voltage regulator are gone.
I'm 82 and have never heard of the examples you decribe, but that doesn't mean it never happened.
I have bought just the inserts here,
https://www.mazdapartsconnect.com/search?search_str=rear+wiper+blade+insert
Worked out well. You can also get the whole wiper.
My last understanding of the whine noise after turning off the CX-5 was the fuel pump. I don't know why. For me, normal. Someone else here my know the reason.
On my 2023 I have my auto sesitivity on high. There are times when I wish the lights went on and I manually switch to on. If high means they go on sooner I am not happy with that setting. Not soon enough for me. Should I be on low?
Wife 5'2" and finds seat comfortable. She thinks entry is tad high. She drives a 2005 Corolla which I have to fall into, so there's a difference in what she's use to.
FYI
Received a letter from Mazda notifying me of an extension of the warranty on the fail-safe thermostat inside of suspected coolant control vale. Covers 2018 to 2025 CX-5's, as well as some Mazda 3, CX-3, Mazda6 and CX-30. Coverage will extend to 15 years / 150000 miles, whichever comes first...