I agree with Brian; looking at the photos you can hardly see these 'faults' but perhaps they are more visible when you see the model in the flesh.
As for the metalizers, I don't think they are a good undercoat for other coats especially when applied by brush. I am assuming you used Tamiya type masking tape as I cannot imagine using anything else on fragile metalizer paint. As a rule, I never used brushes in 1:72 scale because the finishes should be very thin and in this weather (humid), it is best to allow more than usual for the paint to dry. You could have 'surface drying' problems which is why the paint lifted with the tape or as you say, the metallic paint did not have sufficient adhesion to the plastic. Having said that, I have used metallizers extensively and masked over them more than one colour application without incident.
As for the top surfaces, you could just correct the camo pattern by moving the masks and respraying the camo colour. I would not take the hard edge rule in the biblical sense - taking the amount of weathering you have put into it, one would be very correct to accept that the hard edge has started to soften in the weathering process.
For one of your first aircraft models, I think you score very highly especially in artistic rendering. I suggested a 109 because the camouflage involves more blending of colours assuming you choose a mottled version.