Yes sailing the Gulf is vastly different than small lakes, but Lake Michigan is a different matter.. and can also have storms and high waves, rather quickly, which have sunk many a boat.
I took a 46' Sport Fisherman I bought in Tampa up the coast back to Galveston in 2004... We had a hurricane coming up behind us... that had crossed FL and weakened. Our first leg was that 250 miles up the coast from Tampa , no intercostal. It was rough. But we could do 35 mph and wind direction not a problem.... It took us 12 hours before we could get into a port and tie up for the night, so our actual speed was closer to 20 mph, flying compared to sailing.
That was basically the only part of the trip, wide open, no place to head in...
to. You might want to stop in Destin, Ft Walton Bch ( try the docks at Helen Back Pizza).
I would plan to do your trip in 12 hour stages (and plan for even shorter stopping points in case things change. Enjoy the ride. If the weather is bad, or you want to see the country head into the intercostal. The Gulf is every bit as entertaining in the warmer months as Key West and much cheaper. There is Freeport, Galveston, Biloxi(great City Docks, do some gambling, take in a show), Lake Charles, Morgan City, New Orleans, and etc. Lots to see... Sail near the coast, takes longer but you miss the unlighted oil rigs and etc.
If you make it to Cape Coral you can stay at my backyard dock...
This summer I'm going to do something stupid also. I'm taking with my wife, a Hunter 380 from Charleston to Cape Coral. I will break it in for 30 days first. I have had it completely refitted after I bought it, when another sailboat on the hard fell on top of it, wiping out all running and standing rigging including mast. I have not sailed in 40 years although have always been boating (grew up on Chesapeake Bay and FT. Lauderdale). Yes it has been surveyed and will be surveyed again.
Make sure you have almost 2 of everything. A good chart plotter is a necessity, and you can use a Smart Phone or Pad with a GPS as backup. I have new 48 mile radar and AIS transceiver and an EPIRB, . I have 2 MFDs, 2 Depth finders, Plus Smart Phone and PAD, interfaced to all my Raymarine equipment, Have XM with weather service. Also have a RIB with 9.9. Have extra fuel tanks and water tanks(collapsible 5 gallon)(and 2 Shaker Siphons hoses), spare winch handles, auto inflatable life vest, even electric winches and a WinchRite. Plan is to average just 100 miles per week or less. Many stopping points plotted out, more than needed, just in case. Purchased Books on the intercostal and anchorages along the way ( you should do the same for your planned trip.. and some are online, great info. maps, docking info , transient slips). I plan to sail close to shore, playing with the on shore off shore winds, and motoring when weather is bad in the intercostal... I have 350 watts of solar panels for charging and 2 banks of house batteries, lots of flashlights, head strap lights, spare clamps, doubled clamped everything, Rescue Silicon self sealing tape for any hoses that develop a leak. Have lots of rechargeable bats and a universal charger, 2000 watt inverter. Ditch bags. 3 anchors. 10 small hanging solar led lights. I have even bought one of the those red/green/white laser Christmas lights after Christmas for 15 bucks, which should make quit a display on the sails. I have 2 VHFs. And of course 2 flare guns and other flares. Also have a portable 2000 watt generator. Spare stainless screw and bolt kits. And I put in all new hatches and opening ports. Engine recently serviced (has just 500 hours). RIB and its engine new. 2 tool sets. Drills. Changed out all lights to LED, reducing power usage about 75% and should not have to change a light again. Did I mention I have a spare prop and diving gear. You don't have to do all of this. Oh and like when I'm going to drive a lot, I will have the 5 Hour Shots to drink, to stay awake if I need to.
So yes, I believe the boat will be prepared, if it does not sink from all this stuff.. It's me and my wife I'm worried about at 68, and that is only being wise. The shore will likely never be off my Radar, at least that's what I have told my wife.
Regards and good luck,
VIPER