Hey Statmanmi,
Nice to see you still are getting into this TV stuff. To answer a few of your questions:
BYU 4K looks pretty good out of Cadillac on RF 19.1 1080P
WBAY, WFRV, WLUK, WCWF and WGBA are looking good on RF 15 (3.0) all are 1080P except WBAY and WLUK which are 720P
W36FH here in TC is Azteca 720P with 3 infomercial channels. The #4 channel has old movies.(MMN)
RF-23 in TC translates WFQX all 8 channels.
I see RF-31 up north has color bars.
RF 16 & 27 here in TC is up with QVC in SD on the first .1 channels
RF 15 is stronger in 3.0 mode than it was in 1.0 mode running same power level.
That should give you some reading to keep you busy.