Compression ratios in sound studios run from 1.5 to >10 (one box would even over-compress, make big small and small big). Ratios 4:1 to 10:1 are used to restrain over-enthused singers so they “sit in the mix”. It is very probable you do NOT want 4:1. The old literature on WDRC seemed to like 1.5 maybe 2. This is also where I would go to map a wide-range performance “linearly” onto narrow DR media (cassette tape), though cheap tape generally did not sport WDRC.
How much floor-squeak and refrigerator rustle do you want to hear? While ‘normal’ ears can hear 0dB SPL, the background ambient in most homes is 35-45dB SPL; and the very young ignore or discount those very soft sounds. You have not heard them in years. Empirically you set base gain to get these sounds just-audible, and the first knee not much higher. A 2nd knee was a luxury in my old job, but would go at the louder part of the meat of the performance, to shave over-peaks. 62 seems low. I’d have to think on it but it’s late.
They mean different things to different people. However “Dual” used to be a very specific meaning. A semi-syllabic, 0.1 second, time-constant so peaks did not distort (tape, transmitter, phono). And a longer, 1 sec, TC so a sustained loud sound would be ducked and not pop-up at every break. The two together can work Amazingly Well. I am so glad I invented it in the 1970s. (Based on a $$$ product from the 1960s, which turns out got it from a product in 1938…)
YOU want to play with those compression ratios. However I agree completely that this +plus+ the strong EQ and a rather opaque “set of knobs” means you will make a muck-up before you get good at it. I have spent an hour+ setting-up compression on a 10-minute track. With less controls than modern HAs have hidden away in their bowels.And some fairly awkward artifacts.