1080: i vs p - and framerates - what to use??

Damn, this seems basic but have jumped from 25yrs of Beta SD into RED and now trying to come up to speed with format/recording options.

Beyond what a specific client may request for framerates and format, is there any ONE "ideal" shooting setup that one can at least START with? Frankly 90% of our clients could care less so I just want to shoot that which will give me the best options.

Most work is local/statewide TV broadcast (ironically, final output tends to be SD), but we also have national HD broadcast clients too. Most of our work is corporate and commercial.

1080p "seems" to be the default "best-of". True? (yes, am aware of obv 4K+ RED capability, but intend to shoot mostly via Sound Devices PIX recorder, which maxes out at 1080).

Here is what was advised, as far as conversion options: (ie where to start from, even if you need to re-convert footage later)
"This is from best to worst..
1. progressive on progressive
2. interlace on interlace
3. progressive on interlace
4. interlace on progressive"
Thoughts?

Framerates:
Obv with Beta/SD I have been a 29.97 guy forever. Of course there is the on-going "24fps-is-best-filmic-look" mantra (or 23.xx).
Is it better to shoot 24 then if needed, convert to 30 (or 29.97), or vice versa?
What about 1080p60?
aaak!
confused!

Many thanks in advance...

Stu Aull
Alaska