Re: Piling up of my line
You are dealing with common issues. I'll try to shed just a little light on what they are then let some experts provide you with more detailed advice.
In general,the leader piling up at the end of the cast is the result of inadequate line speed/energy to turn over the leader as an extension of the line. Assuming that you are not tossing heavy flies. It is also possible that the leader is not matched to the line and fly combination.
The knots in the tippet are referred to as "wind knots". They result from timing issues. The most common is applying too much energy too soon on the forward cast. This creates a tailing loop which folds back over itself.