Be a pity for such a nice board to get smashed up,however the main problem you will face is when learning to get in the straps as they are quite outboard and do not have enough strap positions for a learner.
Have to agree with Westozwind,buy a cheap learner board,keep this one for a light wind slalom blaster when the experience curve has shot up.
I do know this board and it is in really good nick
To answer part of your question the board works with 50-56 cm fins,best with 8.5-10 metre sails.