Question about the Queen's Gambit

The Queen's Gambit is my main opening with white, but whenever I play it I always feel awkward about the status of my dark-squared bishop. Most times, I'll pin the knight on f6 with Bg5, they'll play h6, I'll move back to h4, blah blah blah but after looking at chess.com analysis it said that blocking in the dark-squared bishop with e3 wasn't a bad idea. If I were to, should my plan be to fianchetto it on the a1-h8 diagonal? For visual representation, this is what I mean. 

move pieces

Yes, if you were to play e3, then putting your bishop on b2 would be the idea. The logic is that Black eventually wants to get his c-pawn to c5, to challenge your central d4 pawn.

When that happens, the central pawns will be in tension and the center will eventually open up, leaving your b2 bishop placed well to eye the center along the long diagonal.

And if Black doesn't manage to challenge White's center with ...c5, then White can pursue other plans ... such as exchanging on d5 and then using the semi-open c-file for piece play. Or perhaps advancing with e3-e4 when the time is right. Depends on what Black is doing.

Bg5 or Bb2 are just different ways to develop. One isn't necessarily "better" than the other, since there aren't any immediate tactics available. They just lead to different middlegames.

Bg5 is generally considered, since the late 19th Century, to be the most active place to develop the QB. These days, a lot of people are playing it to f4, but while this is OK, is seems to be aimed at Q-side play (c7) instead of destabilizing black's center/kingside. Playing an early e3, blocking in the B, is one way to handle the position, though then it needs to go to b2 or even a3. The super lame Nc6 in your game example shows that black there doesn't know how to handle the closed game in general.

Nc6 in d-Pawn openings isn't a great move, but it's probably not as bad as its reputation.

It aims for a Pawn break with e6-e5 instead of c7-c6.

Another point of the Bb2 fianchetto is to play the Pillsbury Attack (Ne5 followed by f4) when the Bishop at b2 is well placed to support the Pawn on e5.

The way to understand concrete opening is to study grandmaster games opened with it, To learn about queen gambit you can study games of for example: Tarrash, Rubinstein, Botvinnik, matches Capablanca - Alekhine, Karpov - Kasparov, Kramnik - Kasparov, Kramnik - Topalov, Anand - Kramnik, Anand - Topalov etc. etc. Nobody can undestand openings and generally improve in chess without studying grandmaster games.

By the way, maybe i am too harsh, but if you condider playing e3 befor developing c1 bishop even for one second, it means yoj know absolurely nothing about queens gambit.

Aha, you meant queens gambit accepted, there is a line with e3 without developing bishop. I was thinking about queens gambit declined.

One of the ideas in the QGD is to exert pressure on d5. Bg5 is a strong move but I like to keep my two bishops so I will retreat it and try to keep it on the board rather than to swap it for a knight. That gives me an option of which bishop to keep, later on in the game. However, in positions where white has played b6, it's more normal to swap it for a knight because in such positions, black's knights can be very annoying to white.

This doesn't look good for white AT ALL. You don't develop the c1B early and it should be quite happy on c1 for the time being. Of course I was discussing the QGD.

In the position you show, white hasn't played very strong moves. 1. d4 d5 2. c4 dc 3. Nc3 is rather weak for white but it was once a recognised line. However, playing Bf4 on the 4th move is poor for white, who can play either 3. Nf3 and 4. e3 or instead, 3. e3, which is very different since it invites 3. ... e5 by black, which leads to a very different type of game where white has an edge.

It's the normal procedure (e3 first) in the Queen's Gambit Accepted (where black plays 2. ...dc). Black can also transpose into a Slav and again, an early e3 is normal there too.

As you correctly wrote the whole sense of the queens gambit is to pressure pawn d5 and developing bishop to g5 is integral part of it. If you hate exchanging bishop for knight f6, play another opening, queens gambit is not for you.

I play the Queen's Gambit, usually with the following move order:
1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Bg5 Be7 5. e3 h6 6. Bh4 0-0 7. Rc1

I find it to be the strongest move order in general. There are deviations: for instance if black plays 4. ...Bb4, I would play 5. Nf3 as a waiting move.

If black plays an early b6, however and hasn't already played h6, I might then take on f6. But in general I prefer to play the QGD with both bishops on and with Bg5. I tend to play aggressively and also like complicated positions, so I'm usually mounting a massive K-side assault if I can't find lines to outplay black on the Q-side. I might choose to swap off the light squared bishop if conditions suit it.

I think it's incorrect. Certainly white is not winning in that variation or else it would have been a recognised main line.

What black DOESN'T do is play the ridiculous Nc6.

Nc6 CAN be played in the line 1. d4 d5 2. c4 dc 3. e4 Nf6 4. e5 Nd5 however, without c5 being played by black. I sometimes play that line and it's fine because black no longer needs to break up white's centre, which should be weak enough for near equality anyway. White has a bit of an edge but that is all.

I'd say it depends on the reasoning.

If a player is rushing to e3 because aren't aware that Bg5 is the main line, then they would certainly do well to learn a bit more about the QG.

But if a player chooses e3 because they intentionally want to deviate and stroll into Colle waters? Then I'd say it's completely fine.

A lot of chess these days is about recognizing that it's a draw any way you slice the pie - so it's less about finding the optimal line, and more about prodding at your opponent with different variations and structures, to see which path(s) they might struggle with the most.

Given the choice, I'll usually choose the less popular/less known approach.

Defending the pawn with b5 can transpose into a very good line of the Slav, called the Noteboom Slav.

However, if white has played Nc3 in the Queen's Gambit Accepted, the normal action to attack black's pawn on b5 by playing a4 is now dodgy because black has b5-b4 and although white gets the pawn back, the b4 pawn hits the Nc3 and it has to move. It shouldn't have gone there in the first place! Black gets equality in a rather confused position.

In the game in the opening post - black played Nc6 on his fourth move - blocking his c7 pawn.
Such Nc6 play - in good games - is more common in e4 e5 games.
In games featuring d4 by white and d5 by black both very very early in the game -
black often benefits by getting his c-pawn in the game early- instead of blocking it with the knight.
black often plays his b-knight to d7 instead - or to c6 only after his c7 pawn has moved and is somehow not on c6 (that part obvious) ..
Note that the c7-pawn having moved - mobilizes black's queen.
And c4 in the Queen's gambit mobilizes white's queen.
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I read in an opening book a long while back that in the queen's gambit - white often gets any of five types of advantage.
Superior development - Qside bind - minority attack - Kside attack with pawns and Kside attack with pieces.
Huge idea in the Q's gambit. Black can prevent it.
And does. 1) - Nf6! and others.

Where black defends the pawn with b5 and white knows the openings enough to know not to play Bf4 and then Nc3 (because it's awful) then white attacks the b5 pawn with a4 after playing a few developing moves and if the pawn on b5 then advances, white can play Nbd2, which is very strong in that position because it can infiltrate the Q-side from there.

Bg5 is NOT mandatory for White in the QGD,

It's a line. But e3 (leaving the Bishop on c1) is also a line. Against the Slav Defense (an early c6 by Black), it's the MAIN line.