Just been getting into buggying myself the past few months - after having playing around with a 3, 4m before that.
I agree, definitely a good idea to check the length of lines every few months.
Tip, if you're melting sleeve ends, on replacement or whatever, use a piece of wire to keep the weave open.
With the line lengths and also tuning, your kite should be able to sit quite nice into the wind- depending on what you own (some are better than others) - don't forget the safety gear.
Just had my first majorly obe the other day, a friend watching said it was pretty spectacular, and while I was wearing a helmet, the knee pads sure aren't going to help you if they're only looking after the car.