I think you're being a little too hard on yourself Max !!! You've done a very good job on this build. I agree with the others about the weathering chips not being excessive at all and like Eric has pointed out, a little more around handles, hatches, areas where the crew walked wouldn't be unheard of. A little more dryburshing would help out too.
As far as the tracks go, two things. To get the sag in these types of tracks you can tie them down with string ran between the road wheels. And one thing that I did notice is the joint is on the bottom and becomes very visible there, you may want to turn the track so that it is on top and less visible.
All in all a very nice piece Max ..... and as I have often seen here, an improvement over the last build you did.
P.S. Read the thread about the Alberta Meet in Off Topic Discussions
Happy Modelling and God Bless
Robert