I have never had a planted tank before and I'm so used to using the gravel vac that I only just realized - how will I use the gravel vac with a planted tank? Won't I disturb the roots of the plants? Should the plants be able to use all the waste and uneaten food as fertilizer?

I never have gravel vacuumed any areas of the tank where there are plants planted. As you say, this will uproot the plants, or even if it doesn't completely uproot them it would disturb the plants too much and they won't like that. They also need the waste as fertilizer unless you're using other fertilizer.