First Over the Board Victory against a Master

I finished a recent four round game in 90 minutes tournament with a victory over a USCF life master. To be sure, my opponent's rating has slipped below the master level in recent years, but a master is a master, right?

I was better most of the game, but got in trouble in a time scramble and only won because my opponent missed a tactic. All things considered, it was a relatively good effort. Some areas for improvement are:

1. Try to make promissing lines work! I gave up too early on the 13...Nxf3+ line, which was winning.

2. When defending against a blockaded passed pawn, consider playing around it rather than focusing on eliminating it.

3. Try to avoid time trouble as bad decisions inevitably result from it.

4. Don't assume that trading off pieces is always best under pressure or to realize a pawn advantage. (See moves 15 and 34.)

Finally, if anyone can explain the merits of 26...Rd3 or 28...Rd3 please do so. I don't understand this computer suggestion.