Get it in writing!
If QFLink are indeed offering cadetships to QF then make sure you get that in writing.
Whilst you're at it, you could also try and get it in writing that your seniority starts at mainline the day you join QFLink......that's a hell of a way to assist in retention! Oh wait, I forgot. There are HEAPS of QF drivers who reckon that you shouldn't get a seniority number until the day you join mainline. Ah well. That also stuffs up all those flying instructors that QF was going to take on but wanted to stay flying instructing on $75-80K a year for a couple of years and then bring them in with a protected seniority number.
(Sorry, I should know better than to be cynical on someone else's thread...particularly when it's got the potential to 'thread drift' as badly as this issue does!).