Help with computer analysis

I recently played the above game and got the computer analysis done.

I have a couple of questions about the suggestions/comments made by computer.

1.)After computer suggested continuation on the 9th move :-

9. d5 exd5 10. Nxd5 O-O 11. Rc1 Re8 12. Qb3 Nxd5 13. cxd5

How does white hold moderate advantage as commented by computer after 13. cxd5 (Although this comment is not visible in the game I posted above)?

2.)After computer suggested 16th move,

16. Bc2 Ra8 17. Qb3 Rb8 18. c5 Qe7 19. Rac1 Rfc8 

What purpose does black's 19th move i.e. 19..Rfc8 serve?

Thanks!

Edit:- how do you get rid of unwanted underlines?

The computer assumes best play from both sides.  I once had an analysis done where in a move where I took a rook with a knight, the computer said that wasn't the best move. 

Well maybe it wasn't according to the computer, but common sense tells me that if I see a rook which can be taken by a knight it should be taken! 

These underlines are very strange as they generally mean a hypertext link and what are underlined above don't link to anything.

I checked the source code and there's nothing I can see that would cause the underlining.  The only thing I can think of is there's a "behind the scenes" .css file or something of that nature that causes certain "classes" to be underlined.  In this case everything that's been underlined has a class name of: gotomove (see in red below).  If chess.com has the site set up so that everything with that class name is underlined, then this is why it's occurring.  There's nothing you can do about it that I know of.  However, my knowledge of html and web design is very limited.

id="chess_com_diagram_1_396255_MoveList_alternate_3_gotomoveid_3_1" class="gotomove">9. d5</a></span> <span id="moveList_2"><a id="chess_com_diagram_1_396255_MoveList_alternate_3_gotomoveid_3_2" class="gotomove">exd5</a></span> <span id="moveList_3"><a id="chess_com_diagram_1_396255_MoveList_alternate_3_gotomoveid_3_3" class="gotomove">10. Nxd5</a></span> <span id="moveList_4"><a id="chess_com_diagram_1_396255_MoveList_alternate_3_gotomoveid_3_4" class="gotomove">O-O</a></span> <span id="moveList_5"><a id="chess_com_diagram_1_396255_MoveList_alternate_3_gotomoveid_3_5" class="gotomove">11. Rc1</a></span> <span id="moveList_6"><a id="chess_com_diagram_1_396255_MoveList_alternate_3_gotomoveid_3_6" class="gotomove">Re8</a></span> <span id="moveList_7"><a id="chess_com_diagram_1_396255_MoveList_alternate_3_gotomoveid_3_7" class="gotomove">12. Qb3</a></span> <span id="moveList_8"><a id="chess_com_diagram_1_396255_MoveList_alternate_3_gotomoveid_3_8" class="gotomove">Nxd5</a></span> <span id="moveList_9"><a id="chess_com_diagram_1_396255_MoveList_alternate_3_gotomoveid_3_9" class="gotomove">13. cxd5<br /></a></span></span></span></p>
<p><span class="moveListAlternateLine"><a class="gotomove">How does white hold moderate advantage as commented by computer after 13. cxd5 (Although this comment is not visible in the game I posted above)?</a></span></p>
<p><span class="moveListAlternateLine">2.)After computer suggested 16th move,</span></p>
<p><span class="moveListAlternateLine"><span id="chess_com_diagram_1_396255_MoveList_alternate_7"><a id="chess_com_diagram_1_396255_MoveList_alternate_7_gotomoveid_7_1" class="gotomove">16. Bc2</a> <a id="chess_com_diagram_1_396255_MoveList_alternate_7_gotomoveid_7_2" class="gotomove">Ra8</a> <a id="chess_com_diagram_1_396255_MoveList_alternate_7_gotomoveid_7_3" class="gotomove">17. Qb3</a> <a id="chess_com_diagram_1_396255_MoveList_alternate_7_gotomoveid_7_4" class="gotomove">Rb8</a> <a id="chess_com_diagram_1_396255_MoveList_alternate_7_gotomoveid_7_5" class="gotomove">18. c5</a> <a id="chess_com_diagram_1_396255_MoveList_alternate_7_gotomoveid_7_6" class="gotomove">Qe7</a> <a id="chess_com_diagram_1_396255_MoveList_alternate_7_gotomoveid_7_7" class="gotomove">19. Rac1</a> <a id="chess_com_diagram_1_396255_MoveList_alternate_7_gotomoveid_7_8" class="gotomove">Rfc8 </a></span></span></p>
<p><span class="moveListAlternateLine">What purpose does black's 19th move i.e. 19..Rfc8 serve?</span></p>

______________________

2.)After computer suggested 16th move,

16. Bc2 Ra8 17. Qb3 Rb8 18. c5 Qe7 19. Rac1 Rfc8 

Edit:- how do you get rid of unwanted underlines?

1. Black's pieces lack mobility. White controls the center and has free play. With vigorous play, White should maintain a lasting advantage that eventually will result in gain of material or better endgame.

2. Black's pieces all aim at the queenside. 19...Rfc8 prepares a pawn storm on the queenside, perhaps giving Black some much needed counterplay.