l just got last year is model of the burton custom, it is new never been used but it is been in the case for a year. Is it okay to ride it still with the pre factory wax that was applied to the board?

It is not mandatory to wax your board. However, it will increase your speed and semi protect the board from scratching.

A way to test yourself how well the board is waxed it to put a bit of water on it and press and slide your finger down it. it if makes a squeak then its good. if it slide right down its good but if there is decent friction you might want to get it waxed again

Yes even if it is new you should still wax it, Most boards do come pre-waxed however it is just a thin amount of factory wax meant to act as a protective layer from dirt and dust while sitting on the shelf, It wont even last you a couple runs. So yes a proper wax job should be done to the board for a smooth fast ride.

Just get it waxed. Riding a waxed snowboard is riding, no wax your gonna have a bad time.