I have a friend who hunts carp from a stand up kayak, he does really well with it, and has had his kids doing the same. As for the reel mount, if your bow has a gadget hole in it use it, there will be a small bit of weight reduction, it also depends on the type of reel you are using. A drum, bait reel is better with a gadget hole in the riser, the Retreival reel, I like with a strap on side plate.
As for what to do with em after you shoot em, we take a filet knife stick it in m and pop, "cut" the air bladder, this will allow them to sink and become fish food. Just my opinion, but leaving them on the shore for the coons and foxes, is just another form of littering, and tends to further a negative bias towards bowhunters, to others that use the waterways.
Thanks,