I like your original idea of weighing down the branches, though rather than attaching weights, I would tie them to long strings (make sure to use a loop, rather than tying the string tight) and attach the strings to rocks or bricks. Four branches would be idea, as you could get a nice symmetrical tree out of it. I've tied down most of my trees (close to horizontal) and in a few situations I didn't leave a central leader. Those trees are now relatively low (7-8') and fairly wide. Of course how big the tree gets will also be dependent on the rootstock.

Those leaves are normal in the fall. In general foliar diseases of fruit trees are only a concern early in the growing season. Right now the leaves will fall off healthy or diseased. I won't even call those spots disease. If as I suspect they developed in the last 6 weeks that's normal aging. If they developed in May-June it's disease. Your tree looks very healthy for December. Holes in apples could be coddling moth. There are organic controls of many kinds. Bagging with ziploc bags is one approach.

I searched for it and got a ton of results, but I do not see that forum listed alphabetically. Can you provide a link to it?

I agree with mikeeatplants. Muscadines would be a great idea. They basically are very large grapes that grow in loose bunches and are disease resistant enough to be grown in hot and humid Florida. They are sweet with very good flavor, better than store bought grapes. Based on that description you might be wondering why they aren't more popular. The reason is that they have very thick skins, (my guess is 3-4 mm) and the skins are very tough. The skins can be eaten but aren't very enjoyable to most. Many also have seeds, so there are some drawbacks but I think the flavor is outstanding. They can't take winter temps much lower than US zone 7 but you should be alright assuming by -10 you mean -10 C not F. Here is a short description from http://gardeningsolutions.ifas.ufl.edu/plants/edibles/fruits/muscadines.html. Muscadine Grapes If you're interested in growing grapes in Florida, then look no further than the muscadine grape, native to our state and other areas of the Southeast. Sometimes called scuppernongs, these grapes are popular because they have a high degree of tolerance to pests and diseases and can be grown with minimal or no use of pesticides. Muscadines differ from the bunch grapes found in the produce section of the supermarket in that they are thicker-skinned, somewhat spicy-sweet, and are picked individually from the vine rather than in bunches.