Hello Jvv, and 1dayfit.
I use the route that was devised by someone on here. Starting at the top of the hill, and ending at the beach. I always always have trouble getting the beach ball at the top end of the beach after the ruins. It does my nut in, because i end up cycling what feels like aaaages out my way, just to get back to the grass, sometimes i end up circling about. Yep, that bit's a total disaster for me, and I wonder if I can find my own route that starts from there instead, I'll let you know if i ever do.
Oh, Oh something I was going to say. Once, I managed to dive into, therefore drowning....hmmmmm, in the lake by the castle. You know the 3rd ball you go for if you are coming down from the hill, and when I reappeared, I was on the road close to the tunnel you need to go down to get back to, that's behind the waterfall, which was fairly helpful time wise.
If by erratic you mean, crashing into ramps, walls, tree's, rocks, Mii's, then yes.

I just get too excitable.