I know a LITTLE about this because we see customers move cars from one state to another. I cannot speak for the insurance part, but the titles part I see on a regular basis.
Every state seems to have different rules. Basically his name will have to be on the title if he wants to get Florida plates on the car with a Florida title and registration. The easiest way to do that is for you to sign the paper title you have as seller and send him the title. It would be a good idea to pre-fill his information as buyer as well. That way if it gets lost in transit, nobody could do anything with it because the title would have his information on it. The downside is he will probably have to pay sales tax on the car.
SOME states you could stay on the title with him by having your name in the buyers section as well, or appearing in person at the "tax collector office" to have both of your names on that title....SOME states forbid any non-resident of a state from being on a car title in that state. I just don't know if Florida is that way or not. If you try this, he will still be on the hook for sales tax, if the person at the Tax Collector office is in a good mood, he/she MIGHT reduce the sales tax down to 50% of what it would normally cost since you are just adding his name to the title. I know for sure Florida is that much of a stickler for collecting their taxes because we have seen Florida customers get really upset when they add a husband/wife to a title and the state charges sales tax on a car they already own.
Depending on the state you live in, titles are GENERALLY easy to replace if it gets lost in transit. I would suggest sending it via FedEx or UPS with a tracking number so that it would be a bit more secure. MOST states if it does get lost, it can be replaced for pretty cheap, unless you live in say Wisconsin, they seem to have some CRAZY expensive paper. If you lose an Illinois title, it can be replaced, but it is going to take a long time. The main thing is NOT to leave the buyer section open. If an open ended title got lost in transit, it would be VERY UNLIKELY somebody would go to all the time and trouble to fill in their info, steal the car and make it legally their own, but I suppose it is possible. Filling in his info in the buyer section would make it impossible however. So sending it would be pretty much a "no risk" scenario. You will have to sign it, because if he brings in an unsigned title, they will just send him away and tell him to come back when it is signed. Some states will also require a notary when signing off titles, so be sure to check that as well.