Hi gomam,
I'm not part of the casual workforce but I can assume a couple of things relating to your queries.
Firstly the one months block flying is probably to do with your initial training. I'm guessing you will be online with a trainer to coach you through your first month. And therefore it is a requirement of your training to complete this.
Secondly as far as the requirement for you to make yourself available for 12 days I guess it depends on what you signed up for. If it's in your contract and you said yes then it's legal. You have to consider the fact that Mam are not going to employ you, spend the time and money on training you and then take the chance of having you turn around and say to them you're too busy to do a minimal amount of flying. They are just covering them selves with the amount of staff available to them to utilise.
Hopefully someone in the know will have some solid info for you but realisitically this is what "casual" work and contracts are all about.
Good luck with your flying, hope you enjoy it.
