If you're saving for the long run, it's actually a good thing when the market is down because the more shares you have, the more you can potentially make when markets rise. And over time - decades, not months - the markets rise more than they fall.
Yes, your kids should go to school. No, you shouldn't bankroll their degree whatever the cost. You've spent your life creating a sound financial plan; don't upend it by suspending your retirement savings or taking out a home equity line of credit to pay for a pricey college.
I generally encourage people to make good on debts when they have enough money to repay them. But once a delinquency has been reported to a collection agency, paying it off won't help your FICO score. The damage has already been done, and the blemish will remain on your credit report for seven years.
If you can't afford the upkeep of your home, it makes no sense to do a reverse mortgage. You will just end up having to sell eventually when you realize you can't afford the home, and whether you have any equity left after the sale depends on the size of the reverse loan that must be settled.