Definitely not bad for your first layout, you made use of the whole track, which is nice. There are not too many tight spots, which is nice also. You might just want to tighten up where the barriers connect, especially where there is a tight corner.
I've had that happen before, but only when I enter pits and leave them quickly. If you were using a skin, it's possible that the filename has been written over. (see this thread)
AtomAnt, there is a little edit button on the bottom of your posts. There is also a multiquote if you feel like criticizing more that one person at a time. Please, if I have to see your spam, please keep it in one post, not several.