As of right now, you can only connect 2 surround speakers to a Sonos Soundbar. You could set as many as you want in a separate “room” but you’ll only get 2 discrete surrounds.
I don’t own any Sonos products, so this might be wrong, but I’m pretty sure that if you connect 2 sets of these in to 2 individual stereo pairs, then group them in a multi room set up, you could achieve a similar effect. As for surrounds, no. As for the reason why I don’t own any Sonos products, it’s because they’re so expensive!
Most people will probably buy this to hang on the wall, so that higher position will likely make a difference in sound in comparison with the One SL that sits on the table.
you complain about the wifi setup, SONOS always say your initial setup connecting to your wifi should be done via the ethernet cable provided first and allow the updates etc, so this was your (user) issue rather than the equipment