Does the wallet have to be opened 24/7 or will the stakes be minted next time I open the wallet? Also, if a stake was not confirmed and time has passed do I lose that stake? In other words is there any way to get it confirmed?
You don't have to keep the wallet opened 24/7 but the longer you keep it online the bigger chance to stake.
If a stake was not confirmed that means your stake was not accepted by network and there is no way to get it confirmed. This block will re-stake again, coinage not lost.