There is no problem mixing brands as long as you get a good rear tire why waste all the tread on the front by replacing it. I have done this many many times without a problem.
I am a newbie myself, I have just bought a 16 plate MT09 Tracker (not Tracer) and I cannot find any snatching issue with the throttle. The power delivery is very smooth and the handling is fine on my bike. I have only done around 1K commuting, the bars are a bit wide for tight filtering, I don't...