moving my tank

None. As long as you preserve the substrate and filter media, there is not much that is in the water that you want to keep. The beneficial bacteria are not there, and most of the beneficial micro-fauna will be in plants and mulm. The new water should be of similar parameters (ie, pH, GH and KH, temp), but otherwise, you can go with 100% new water with no worries of a cycle. You can easily move the filter, decor, plants, and filter into a tub, remove the substrate, rinse the tank clean, move it, put back the substrate, fill with water, add decor, bring to temp, and put the fish in. No need to transfer any of the water if you don't want to. If you want to keep some of the old water, minimize the amount, since it will bring with it various other organics (hormones, nitrates, etc).

Yep, very much an option. You'll want to be careful removing the plants, so you don't seriously damage the root systems, but they can be moved. My crypts only melt when they go to a setup that's much different than the source tank, and I use the chance to split off the babies and transplant them to new locations. I'd siphon as much mulm out as you can, settle it to reduce the amount of water in there, and then mix this mulm into the new substrate as a kick start.

It will work. The addition of flourite will increase the nutrients available to the plants, but you may still need to supplement with fertilizers if this is a heavily planted tank. Monitoring the plant color and growth is a good way to see.