Serve - Safin
ROS - Nalbandian
BH - Safin (not by much though)
FH - Nalbandian obviously
Net game - Nalbandian, Safin was dire at the net
Volley - Nalbandian
Touch - Nalbandian
Improv - Nalbandian, you keep repeating your categories
Pass - Even
Movement - equal
Speed - Easily Nalbandian, slim 2007 Nalbandian was definitely faster than pre injury Safin, although neither were known for their speed.
Mental game - Safin
FH. Absolutely not. It's not Nalbandian 'obviously'! Safin's FH has a lot more power and is more consistent; It only became a poor shot after the injury he sustained in 2005 and he couldn't hit with as much power.
Safin was not dire at the net. He just played a baseline orientated game. Safin's anticipation exceeds Nalbandian's at the net, and has made some of the most outrageous volley's I've ever seen. You clearly haven't watched Safin if you believe he was poor at the net. Remember we are talking pre 2005 here before he became useless.
And no. I am not repeating my categories; Net game and volleys are two seperate things (much like foot speed and footwork and Improv & touch, serve and service game). Net game is the package - approach/technique & execution. Not known for speed? Safin was one of the fastest guys around, even though he was big.
Your definition of talent is different than mine I suppose. To me Marcelo Rios is much more talented than someone like David Ferrer for the level of tennis he could achieve.
The indoor courts of Miami and Paris were incredibly slow when he won, they really might as well have been outdoor. Nalbandian had just been building up to that level for a while and that was when it finally all came together. Indoor is Fed's best surface, Djoker has won the YEC and Nadal is a 2 time finalist.
Indoor is not a surface; It's merely a condition.