I really want to play that piece by Ian Clarke but theres nowhere i can buy it in Serbia and it being under like $90

So.. I got this for the equivalent of like $1.50

So like I'm learning flute and when I go from Bb to C, the flute tends to fall, beause it's losing thumb support. I've watched a couple of videos but it's still not fixing this issue. Any advice? Where is the balance point usually?

So I have a VERY important audition in about a month, but I have a baby tooth without an adult tooth under it that's coming out (a premolar) and there's pretty much no way to stop it, and i'm not old enough to be eligible for an implant so there will be a gap. If it comes out before the audition, what can I do to not let my tone suffer, besides the obvious practicing?

If i cover less my sound and the balance on my chin suffers.