Greed is one of the things that slows your development.
Is Being Greedy For Pawns And Peices Bad

Capturing pieces is generally good, but if you tend to go out of your way for them you risk being lured into tactical traps and having your position weakened--both of which are definitely bad. When you feel driven to be greedy with capturing, just remember to stop a moment and ask yourself if there's a better move you could be making.
Play through a few of Morphy's games. He fed pawns to his opponents in return for piece development and activity. They would hoover them up and lose.

As a general rule, the typical way to refute a sacrifice is to accept it. But be prepared to return the extra material (or at least, some of it) if that will end the opponent's attacking chances.

until you only have 3 pieces left...nothing better than killing a wayward queen..what's also good is leaving their own pawns in the way of their own attacking pieces.. sometimes their own hanging pawn is blocking the centre and you definately don't want to take it..of course this is advice from a strong fide rated 657 player.

A rule of thumb that IM Eric Rosen once gave was: when your opponent offers you a free pawn in the opening, it's generally good to accept it. But when your opponent offers you a second free pawn in the opening, you should generally refuse it.
Here's an example of that:
Nimzowitsch recommends against accepting gambits, especially if the capture takes you away from the center. The only time it's OK to go pawn grabbing in the opening is if it is a central pawn being offered. That has long-term development and positional advantages which make it worthwhile.
The Smith-Morra gambit, as showcased above, gives white too much of a lead in development, even declining the second pawn. @Dranged does give the proper response after 4. Bc4, but even then after 5. Nxc3, white has plenty of compensation for the pawn.
A better continuation after 1. e4 c5 2. d4 is to play 2. ..e6 immediately, which transposes to a favorable line of the Benoni. Now any pawn move white can make will weaken him in the center, so he will likely just continue his development with 3. Nf3 (most common) or 3. Be3.
I need to know if its greedy because i do it a lot.