Can I get some quick trusty advice on a dripping gas 40 gallon hot-water
heater?

I noticed my hot-water heater leaking and my husband is out of town.
He says wait until he comes back (1 week) but I am afraid something bad
will happen. He also says maybe we should replace with an instant on
tankless heater but I want to get it done today!

Do you have quick advice on hot-water heaters?

1. If it's leaking cold water from the bottom but still working, is it not
repairable (I assume it's a throwaway item).

2. It's at least as new/old as when I moved into this house around 2000 and
it has an energy efficiency sticker so it's not that old. But, would you
replace it with a bigger (only two people in the small house as the kids
are gone) one or even go tankless?

3. Is it a home repair or, due to gas, is it only by a qualified pro?

4. Do most of you go to Home Depot or the like and just pick one and have
them install it or is there a "better" way?

5. I never did anything preventative but googling talks about a sacrificial
anode and draining; should I have done that (I'm guessing yes).

6. If we go tankless, are there "gotchas" we need to watch out for?

Sorry for so many questions!
But it would be nice to get your off-the-cuff advice again!

Donna