Does a multi-entry tourist visa to Thailand reset for another six months if I re-enter before its expiration?

You can stretch it for 9 months if done properly but you applied a little early

No, it doesn't reset for 6 months. You get 60 days upon entry and you can extend those by another 30, but then it's over. All in all you can get just short of 9 months out of the visa if you time your entries optimally.

Nope, you get 60 days for each entry throughout the validity of the visa

No, it never resets for another 6 months. The dates on the visa will never change. That is the visa that the embassy issued. It's effective for 6 months from the date it is issued. You really should have waited a little closer to your trip to apply for it.

EVERY time you enter Thailand through March 9th, you will receive an entry stamp for 60 days. Each of these entries you can also apply for a 30 day day extension. So after 60 days (or 90 days with extension) you must leave Thailand. You can then return within those dates and get another 60 day stamp. You can repeat this as many times as you want until March 9th.