I have to believe that if I spend $700 on a bow I would be happy with and learn to shoot it well no matter what brand it is. So initial performance is not my concern,
First and foremost , DONT assume a bow will grow on you the more you shoot it!!!! "Initial performance" is priority one period!
Also , there are so many quality bow mfg's now that I feel your cheating yourself by only looking at the three you've mentioned.
To try and answer some of your questions as honestly as I can based on my own experiences I'll just lump the important ones in one reply rather than covering each concerns as numbered.
First , I dont believe any of the mentioned bows hold any strong evidence over each other as to what cam system is better than the others for tuning or durability.
Finding a proshop that will promise lifetime tuning is not out of the question if you purchase the bow and accesories from them.
The difference in limb styles (split vs solid) is purely personal preference.
Being as big as you are , I personally would choose the longer axle to axle bows. The Switchback wouldn't be on my list. The Mathews Ovation however would be.
I believe Jons Sport Shop in Oshkosh carries both Hoyts and Mathews. If I'm wrong then Old 45 Archery in Hortonville carries Mathews. The Archery Shack in Neenah carries Bowtechs as well as The Sportsmans Lodge in Appleton.