Need Good Advice

That's a tough laundry list to cover. I think the biggest problem is going to be the tow vehicle. I believe the max tow rating for the V6 was 5000lbs and 6500lbs for the V8. You won't be towing anywhere near a mobile home with that.

I'm 6' 4", 240lbs. So I would need something towable to accommodate my height for inside dwelling.
You'll be rubbing your head in a lot of regular TTs. Try to find a model with the rounded barrel type roof for more headroom. Common to newer trailers. You'll find the mattresses in TTs shorter than standard too.

Need something with a decent kitchen since I do bodybuilding and cook and store meals in bulk, so I'm guessing I'll need a spacious refrigerator.
Not many TTs have a lot of counter space either. You'll want to invest in a sink cover for more space. Finding a large fridge in a small TT will be even harder.

Want something that can't be easily broken into.
Don't think this exists in an RV. They're all easy to break into. Heck, most even use the same key for the storage compartments.

Don't want a mobile home too large to be a pain to tow around.
Again, your tow vehicle will limit you to a smaller TT

Would like something that doesn't require a lot of maintenance, if that's possible, but something that isn't going to fall apart but also last a long time.
Do you plan on living in this year round? That poses a whole list of problems for your location. Most RVs are not considered 4 season capable. They are not insulated well enough and you'll have to winterize the plumbing.