Yeah you shouldn't have the ladder on the outside of a tower even with riggers.
While it might seem like money for old rope I'd advise anyone to take a PASMA course at least once in your working life. Most sites require it regardless if you're using towers, renewable every 5 years. Stealth tax if you ask me keeping people in jobs but never the less very educational.
Do u mean the tower or the anchor in wall? Surely the higher the better.Your idea of wrapping the rope around the anchor point is not sufficient, the rope can move or slide around it.
Learn some decent knots and hitches and tie it more securely.