The area the break was will be stronger than the bone around it. It wasn't a spiral fracture so should heal pretty crisp and then its all about getting the muscle and ligaments/tendons back into shape. He's going to be fine and I think going to surprise a fair few people on his return!

Would you risk him playing again if he still has quite a few weeks on the side line or wait till next season make sure the injury is Fully healed?

He wont be rushed back, think thats fairly certain - dont think any Full time RL team would even try and rush someone back early with this type of injury for just afew league games. If hes ready he'll come back, if hes not 100% ready he wont.

short term contract to prove his fitness well being?

He is a risk, but he is British and he has shown some good signs since coming back from union, nothing like he was, but he might be worth a match payment deal.

He's British, still youngish and a better than average player.
One year deal on vastly reduced money but maybe with incentives and you have a player hungry to pay back and hungry to prove. Win win for us and him.