The slav exchanged is usually played AFTER white develops his knight to f3. but sure lets see how this goes on.

a6 and a3 are weak. wasting tempo rather than developing

h6 is even more poor than a6 because additionally to wasting tempo,black weakens the kingside where black's king is suppose to be protected.

black would usually make a symmetrical line by mooving black's bishop to f5 just as white moved his to f4. but because black wasted two tempo moves now white can play Bd3 and black can not do it. white is allready slightly better here.

9.Nf3 can be considered slightly better as an attempt to control the central square e5. but i guess now white can try to play f3 and e4.

Na2 is slightly innaccurate. The reason is that you want to have your knight as close to the central as possible because they control more squares. in this case the knight was watching over the d5 and the e4 square. i would however love to see white cary on his central assault instead with 12.f3 or just simply give his bishop some air with f3.

nah. the light squared bishop has dropped in value in this position. it is shut it and that is black's problem. it has to be liberated soon. Bb7 might have been slightly better to stop white from playing f3 and e4.

like i said. f3 is probably a better escape hole because white can play e4 as well, but still good thinking. doing prophylactic mooves can be vital. Editted: i just spotted that white's escape hole on h2 is not so bad too because white's bishop may want to stay on that diagonal.

black's queen is not dooing anything on a5. i think black should focus on controlling the c-file now that white has both the black squared bishop and the rook attacking it.

another reason why white might have wanna play f3 earlier. Now however,since both h3 and f3 is played, white has weakened his kingside a lot more than originally.

well this is poor. white can easily protect the bishop and suddenly black's knight is poorly placed. as i described earlier,knights are best placed in the center

now you realize!

nah. Rfb8 is not that good since black needs to place one of his rooks on the c-file to contest it. here black realizes that he wasted tempo missplacing the queen and tries to repair the damage.