Francois, you allready pointed out that it all needs a flat coat. What paint do you use, this looks like gloss paint in the pic's?
Few points to look into.
The inside of the hatches (turret) was painted the same color as the outside of the vehicle, so as not to stand out to much when they were opened.
The tracks look very shiny, silvery. Try painting them in gunmetal, and then drybrush lightly with a silvery color. I use Boltgun Metal from the Warhammer series.
The infantry soldier is pointing his gun into the ground. I would try to reposition either the rifle or the arm to raise the rifle. Also his Ammo pouches are in the wrong place. They would be attached with the lower part of the pouch to the belt, covering the upper pockets of the jacket.
Advice on weathering, well, you can go as easy or wild as you like, depending on how you will display your model. In a dio, a vignette or on it's own. It should then blend in with the groundwork and general surroundings. But as a general rule any model improves if you ligthty spray a thin coat of something like buff or Desert Yellow along the lower part of the model and a little more over the glacis plate, to give a dusty appearance. Drybrushing those colors will bring out the surface details and give the model a nice 'texture', which makes it look less 'toylike'
Ther are a lot of articels relating to weathering on this site, under features or in the forums, best to do a google on the left, to help you along.
Some inspiration
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He I like what you did with the driver behind the visor!
It's looking good sofar, and with some weathering it will look even better
Cheers
Henk