Yes, it is still called three-betting (to a tiny size), as you have re-opened the betting for the early position raiser to now potentially re-raise (or four-bet).
Definitely not something I'd encourage continuing as you progress in stakes, early position raisers are supposed to have the strongest ranges as they have the most players behind them who can pick up a better hand.
You stand to lose extra when they do have a monster and re-raise and your small re-raise will offer them great
odds to continue with whatever hand they do have, so you are never winning the pot pre-flop which is often a decent result in NLHE.
To answer your other question, there are standard raise and re-raise sizes for a reason (there is a lot of information out there on bet sizing). A min-raiser is offering great odds to the big blind and others at the table to outdraw what should be an above-average starting hand.
Think about the odds your raise is offering your opponent: If you raise smaller you are giving your opponent very good odds to continue... if you raise bigger you are risking more chips and can even price out the hands you are beating and you want to call you, thus you end up only playing against hands that have you beaten.
Good luck to you!
