Also FYI, don't worry about not hearing from DSS. Many do, some don't. I don't mean that to sound like it's an excuse or that it's "OK" - it's just unfortunately the way it is. It happened in the pre-DSS setup as well.
I don't personally use DSS for 180 day reservations (easy enough to do myself), but the reports on this thread from those that do 'generally' tend to slant positive. You'll occasionally see a bad report, so it's not all perfect, but I think you're in reasonable hands if you do try it. Although I think a lot of people just prefer to do it themselves so they can adjust on the fly when needed, but maybe that's just my perception.
As to dining - 2 and 4 are tough dining ages, or at least they were for us! PBJs in the lounge vs trying to make an ADR and worrying about our kids behaving/staying awake usually got the nod from us! Yes, parents of the year.
That said, some of our favorites have been:
Tiffins lunch, love that place, and yes, even with the kiddos (oddly, my picky eaters like the food there)
I took both kids to Teppan Edo in October and had a BLAST - I know it's cheesy and all, but it really kept them engaged
Be our Guest dinner (not so much a fan of other meals there)
Garden Grill breakfast (the best character interaction we've had in our travels) (Prefer PPO)
Tusker House breakfast (prefer PPO)
It's funny, traveling with younger kiddos, I have cancelled far more ADRs than I ever end up keeping once there, so I don't consider us particularly well-rounded in all the WDW dining options!
Happy planning!