Perfect pawn structure and a two Knights for a Rook trade - right or wrong?

I think the title pretty much says it all. Anyway, here's the relevant game:

i think d5 instead of c5 would be better to keep the knight there and not trade 2knights for rook

In relation to the position after 13... Ndf6!? 14. Rfe1 you wrote this headline:

Perfect pawn structure and a two Knights for a Rook trade - right or wrong?
 
There is just one thing regarding that pawn structure which is that black can hardly move the rooks. It is a type of position that is well suited for the knights and now black has none. But a good point for black is that white's knight on a3 can't go to any good place. Thus both players need some time to rearrange their pieces and their position.

You asked this question:

As for the position, a question follows: should Black try and delay the exchange, say, by playing 14... Bc8!?, intending Bf5 next, when after White's Nd2 the full exchange still takes place?

I suppose you mean:

14... Bc8!? 15. Rxe4 Bf5 16. Nd2, or white might prefer to keep the knight on f3 and instead play 16. Bxf6

Well, you get the bishop in action which is good, but you still need to activate the rooks.

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As an alternative to black's move 13... Ndf6!? you suggested 13... Nef6, but why not 13... f5!? Active and aggressive although it could be dangerous for black to move the f-pawn. But nevertheless it looks (to me) a lot better compared with 13... Ndf6!? giving away two good knights for a rook and certainly more active than 13... Nef6. White could decide to also be aggressive and, after 13... f5!?,  play 14. g4. Rather exciting.

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EDIT:

Despite what I wrote above, I think your idea is worth trying out. I mean why not? You will probably get some great excitement as a result, as well as learning new aspects of the game of chess.

Here is an interesting article which I just found via another topic here on chess.com:

The Evaluation of Material Imbalances
by GM  Larry Kaufman
http://home.comcast.net/~danheisman/Articles/evaluation_of_material_imbalance.htm

In that article you can find some ideas on how to deal with the situation rook + pawn against two knights [under the section called TWO MINOR PIECES vs. ROOK AND PAWN(S) ].