B65 is at level 63, any sailor you have that is at least lvl 63 can use it... and for the guns... also lvl 63

Prepare to be disappointed unless you like AA.

It's not that bad. It's quite fast, it's a good gun set up with great AA. Like all PBBs the spread will probably be unimpressive until you're a little higher and it can be difficult to use until your lines match your range, like with all low level BBs. But all around it's still a good ship, better than the Kongo for sure and whether you like it better than the BB2 of your choice is probably going to depend on how you like the IJN BB2 gun placement.

If you know how to play/handle it then yamato is OP. Same goes with SY and Amagi. In general IJN BB excluding Kongo. They are OP with 45 angle gun. "Penetration" *winks* is not in dictionary at max angle.