Tactic justified?

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oozecube2

Worth it? Yes/no and why?
Btw, my opponent actually lossed a tempo earlier on by moving his bishop out, I moved my queen to b3, threatening b2, and he moved his bishop back to protect it. So I guess technically two tempi. In this situation, was this exchange worth it?
aquiredtaste

No, your queen is now momentarily trapped, causing you to use precious moves or premature woodswaps.  You have forced yourself into a middle game you aren't ready for.  All for a crap knight and the a file pawn.  Not worth it.

Shakaali

White may proceed with 4. Bc3! How can black then cope with the threat of 5. Ra1?