Starting the Maillard reaction on ribs without a torch or gas stove
You need high, direct heat.

Option 1 (The practical): Don't think about the candles. Even if you lit enough candles in a pile to get it hot enough- candle soot tastes terrible. Of all the tools listed among your assets only the grill shows potential. Buy some charcoal for it, get it rocket hot, and sear your ribs to perfection.

The charcoal will also add a little flavor. Not much since they won't be there long but more than a torch would.

Option 2 (The MacGyver as requested): Use your paper to make a large (3-5' diameter) paper-mache parabolic dish. Line the inside of the dish with your foil with the shiny side out. Experiment with a sheet of paper to find the focal point of your dish. Move the paper toward the dish until the focused light is a couple inches across. Take your dish outside in the sun and wave your ribs in front of it. Solar blow torch.