I have 3 different projects that I need to address and need some suggestions/ideas.

2. It seems like the previous owner wanted to make the sliding glass doors stand out. The distance between the doors and white aluminum trim is roughly 11". The height between the doors and the top is 28".

I do have plenty of leftover yellow vinyl siding that I can use if needed. Thanks for any and all comments.

Two choises, remove those white "coloums" and have to redo all the siding in that area.
Or just J mould around it and fill in with siding.

Is that doors threshold sitting level with that balcony?

I'd be more concerned with the way he built that balcony. Sure looks like it's not cantlevered correctly.
Those floor joist had to be run under the buildings 2' for every ft. of overhang.

You can fill that with some decorative tile siding..

But first,,,,, Answer Joe's question.. You may have to add supports whether it's from the deck to ground or deck to wall.

(1) what are the chances that the door was cut into a nice virgin wall? if so, the previous owner should have peeled back the flooring and properly sunk in the supports for the micro-balcony. I seem to remember 3 feet sistered to the joists for every 1 foot extention outside from a Holmes show.

(2) did that guy ever do research? all he had to do here is frame the door opening on the inside of the wall, and then cut the hole for the door through the wall. lift up the siding gently and shoot some 3-1/2 coated nails to hold the sheathing. now you're going to have to darn near reside that whole area to make it look right.

(3) rip it out and put in a plain old window if Joe's suspicion is right, and the door is smack dab level with the baby balcony. that will be iced up and/or leaking until the wall falls off if so.