Option 1 would probably be the next best option, but you may lose more of the benefit by trading the slightly stronger pushback with the legs for a much shorter stroke. I think option 3 might lead to back problems, because you're not bracing yourself strongly enough when pushing back from the catch.
With 2, as long as you know what the ideal is, and you're working towards it, you can gradually reduce the butterflied legs, with the rest of the stroke staying pretty consistent over time.
I started in 2003, and haven't lost the gut enough to get to the perfect stroke, but so far I'm happy enough with it. Other parts of my fitness are the limiting factors on performance, along with having to waste watts on shifting the additional bulk up and down. If the weight comes down, the power will start contributing to what the PM5 can measure. My profile picture taken at the 2018 BRIC shows a bit of what my kids called "the bullfrog" pose

Good luck with the journey ahead, you've made the right start. If you feel like joining a team, we're always interested over at the Forum Flyers.
Cheers
Dave