Yes, you could add apple juice and sugar at pretty much anytime, though remember that more sugar isn't always a good thing: more alcohol will make it hotter and take a bit longer to mellow with age. Personally, I would just go with the juice, but if you want to boost the alcohol, go for it. Since you started with honey, maybe add more honey instead of a different sugar so you can get more of the honey quality in it.
To sorbate wait until it is completely done fermenting (3 days of constant hydro readings), rack it, sorbate, and sweeten. If it's done in a week or two you can do it, but if you add more fermentables (especially extra sugar) it could take longer than that to dry out again, so go by hydro readings, not an arbitrary time scale.
Also, remember to sulfite along with sorbate to stabilize.