I have had multiple cars with DSG, and now have the 1 litre +DSG in one car (not a Fabia). Your driving is very much like mine was (in outer London suburbs during rush hour, prior to lockdown)
Normally just left it in D, once I did look at the gear indicator and counted and realised it did about 120 gear changes during each journey due to traffic lights. There were a couple of 3 way and 4 way lights where I would put it into N (as I knew it would be about 80-100 seconds before lights went green)
Never needed S mode in busy rush hour traffic (and London commuters are heavy footed away from lights). I only ever use S mode on country roads if I need to overtake as it gives quicker acceleration. (Just flick gearstick back to change between D and S)
You can move gearstick to side and use manual mode, but having tried it, never bothered again
Fuel consumption varies due to traffic, I used to get about 42-43mpg typically during rush hour, but same route off peak would get 50-53mpg. On one occasion was accident, took twice as long and only got 34mpg.
Out in the country on open roads can easily get 52+ mpg, although does fall a bit if you do 75+mph
I normally use premium unleaded as the 1.0 tsi pulls better at low revs with it, the mpg seems to be about 10-13% better with it (so if extra price is less than 10% more, then you save overall).
I leave a/c on all year, as the dryer helps with clearing screen even when heating on.