I don't why he has that little spike coming out the frame; doesn't that just add more weight to the frame? Even though you wouldn't think it could be any lighter.
You have probably got quite a few air bubbles (which happens quite alot using water) which can mean that the break doesn't work sometimes. Try bleeding it under water (bath).
Start as early as possible! But still there are some class riders who start when they're older. I mean there are bikes like the Koxx Wasp which is designed for young and small trials riders so people can starter earlier.
Same, I hate riding with a front magura. You could file out the drills to make them square, saves a couple of grams, but makes your rims a load weaker! lol
Higher BB rise means the bashguard is obviously further up and therefore there is more ground clearance. So for things like hooking, your bashguard isn't in the way for example.