These are some that I've come up with so far. Yes/no questions seem harder to evade.
-Will model3 look like model S only smaller?
-Will completely custom colors be available in the future?
-Are there plans for Tesla to build electric vehicles for Space X to take to Mars bases? And will Mars superchargers be available?
-Will future upgrade to higher capacity batteries, for S, X or 3, be as simple as battery swap + fee?
-Have you considered covering entire large parking lots (for example malls) with solar panels to power superchargers underneath? Everybody wins: shade & cover for all, free power, more customers.
-Could there be standalone superchargers in remote areas powered by solar only and needing no grid power?
-To what extent is today's supercharger network capacity anticipating future demand?
-Will hyperloop, other simlar systems, and urban redesign etc., eventually make cars largely obsolete? If so, how soon?
-Once multiple gigafactories are running, will you sell batteries to competitors?
-Any update on a Tesla supercar and what would be the maximum likely horsepower number, roughly?
[JRP3's 12V battery question is entirely appropriate and that whole issue is particularly irksome to me. People forget who they're asking - no one is more direct or 'non-bs' than Musk and JRP's wording is pretty tame by that standard.]