ok about the head stall its every where on this site. i got a post locked about cuz theres too many posts on it
heres a good link that should help you.
just practise it. i though it was some spot where the ball had to be but its not. its the lack of practise. trust me. just put the ball on ur head and balance it as much as you can and just keep doing it. and stay relaxed and dont start dumbling eerywhere. be smooth and steady and gently. not too many big sudden moves. after a week or so ull get results no doubt.
about the lance flick, for some reason i dont use my laces i use my toes and i find it so much easier the the laces. just lean forward more and pretend ur tryin to flick the ball the normal way but behind ur back and then when it goes up just hit it down with ur foot. but when ur flicking it dont flick it to hard. be gentle but sharp.
about the back heel juggling, try it barefoot with a deflated ball. dont hit it so it goes to high. try to keep it bum hight. also make sure ur not doing it behind ur back but do it so you can constantly see where the ball is. like this kid:
http://expertfootball.com/gossip/freest ... juggle.gif
and dont try to stay in one spot, u have to keep moving with backheel juggling.
well hope this helps and if you got any question feel free to ask cuz im sure other ppls can answer too. good luck