Very nice, especially for a first kit in 25 years!!!!! If all the PE you used was the Aber clamps and some screens, I am truly impressed! The texture on the superstructure is truly fantastic!!! I can see that you have worked hard to add a lot of extra detail, and it really shows. I think the missing cap on the air filter is great.
As far as suggestions, well it looks like the side of the front hull is not flush with the top. Not sure if this is fixable at this stage, or not… Did you add wire for the s-mine throwers on the hull? The tow hook could be drilled out. If the tank was made before Feb of 1943, there should be visible holes (apertures for a periscope) above the drivers vision port for when the port is closed. One last thing that I noticed was the track brackets for the turret. I will included a pic of how they should look. Give me a half hour or so, and I will load it on my web page, and post it here.
As far as painting… I have had good luck with clear gloss-wash-drybrush-clear flat. If you are using pastes to weather, I would do them right before the final flat coat, but remember that the flat coat will make the pastels quite dull. Or, I have had a lot of luck with just using flat earth applied with an airbrush to simulate the dust on the lower hull. You might want to also add paint chips. So, a final process for my typical model would go something like this: base coat - paint chips – painted dust/mud – clear gloss – wash – drybrush – clear flat.
Hope some of my suggestions help and good luck.