I'd go without the free flap -- The fewer cuts to your throat, the better, and you will get used to the modified tongue pretty quickly.

The free flap doesn't do anything except fill the space where the removed part of the tongue used to be. I don't see any improvement to your quality of life with a flap; in fact, my wrist donor site has nerve damage and often gives me some pain.

Yes, the free flap will be anchored to the floor of mouth and cuts have to be made to do the microsurgery to connect the new blood supply to the flap. On my second flap following my total glossectomy, the blood supply died so the flap died. Even with nothing there, I was able to talk, albeit not as well as before. Sadly, all the scarring from all the surgeries and the radiation have slowly closed down my trachea so I am unable to speak at all, despite having my vocal cords, and I am totally dependent on my tracheostomy tube for breathing.

In short, lots more work, more things to go wrong and not much to show for it when finished.