Depth - It does look like you're going too deep either that or you're going over the same line too many times. You want to get it down to one line one pass as much as you can tbh. There are several blow outs where you lost depth control.
Balance - You're not finding your balance before running a line or you're running lines you aren't capable of lining yet. Practice tracing calligraphy and script on paper with a sharpie, itll help you a lot.
thanks for the reply yeah I feel like I struggle to find good hand placement on some of the lines I pull and that ends up with an inconstant line. pretty much all the thick lines are one pass lines so must be going in too deep thanks for the advice man.