Long Wait-Son will turn above 21, parents (sponsors) now retired - double whammy

[hardlyknown]

My priority date is August 2012. I'm on F3 visa with Indian origin (my parents applied for it - they are both Citizens). Several questions:

1. My son is going to turn 21 this year in September. What are his chances of getting "grandfathered" when dates become current?
2. My parents have since retired. I have a brother-in-law/sister who can provide financial support, but both parents are on Social Security not making enough (below current poverty line). How does that play into this conundrum when the dates become current?

Thank you.
Hardly