And even more

s! The bit in bold sounds like something I would do!

Great way to stand up for yourself!!
My favourite spot in MK is the viewing area in Liberty Square. It's underneath the Liberty Tree, so is shaded; opposite the Hall of Presidents, so you get regular blasts of air con; reasonably narrow, so no one can jump in front of you at the last minute, without standing in front of the rope; and it's got a nice low wall along the back, that the rest of your party can sit on, and still see the parade past you! Oh, and you're not too far from a rest room either, which is always a bonus
As for Illuminations at EPCOT, the viewing areas closest to Future World are the best, I've found. I've never tried the one between Italy and Germany, but I know that the UK viewing area has overhanging trees, that stop you seeing some of the areal stuff. The viewing area near Future World do get busy pretty quickly, though, so stake out your place early.
I've never seen the AK parade, I'm afraid, but the wheelchair viewing areas are marked on the map, as with all the other parks.
Never tried the rose garden, but I've found the Tomorrowland bridge to provide a great view. Just be aware that if someone stands right up against the railing to your left, they may block your view of the castle. I've only had one group do that once by accident, and they stepped back as soon as I asked them to. They were also travelling with someone in a wheelchair, and we all got chatting about travelling the parks on wheels, while we waited for the display to start. There seems to be almost a secret club for those of us on wheels, but it could just be because we're all so grateful to see a face for a change, instead of someone's backside!