Yahoo, keep up the good work!!!
Thanks for posting video, too.
As far as that patience factor that some of our pals mentioned, I certainly agree. In one point around the 1:20 mark (1st video), you simply keep a few shots nice and deep and the other guy sails one. Avoiding the panic button and keeping more of your shots deep in the far end is a significant step in the road to playing a 4.5 level. Even in neutral rallies, steady deep shots will keep opponents "out of your kitchen" more often.
It looks like at around 1:49 you decide to rush the net, but you go about a half-second too late and you catch a ball in your socks. If you pursue the development of some serve and volley skills (I highly recommend it for just about everyone), it's important to explode forward toward the net immediately after your serve. One more thing to practice, right?
While we're talking about going to the net, you've got another attempt at 2:22 where you move in behind a topspin drive. Before you can cover any ground, the ball is already coming back and passing you. Problem? Unless that drive had sent your opponent scrambling big-time, you would have been better off with a slower, low skidding slice approach placed deep. That would give you extra time to get closer to the net. If you don't have that shot (the slice), get busy. You also need it for defense or hitting change of pace while back at the baseline.
A number of your returns of serve are a bit lifeless and landing too short - up around the service line - and server dude is having too much fun with those short balls. Even if you're not crushing them, you've got to punch the ball deep enough to at least start the rally in a neutral posture. Looking at your set position when you return, you're rather stationary. My recommendation is to work on carrying a little forward momentum into your split-step so that you can more easily move through the ball and punch it deeper to your opponents. Fed is one player who does that really well on his returns.