Sounds like a solid set up! Plants can take a lot more heat than expected as long as their roots have plenty of cool, moist soil. Miracle grow soil is meant to be used as is, so you're right on the money. Next season you can top off with more Miracle Grow, compost, or a general soil mix with a little fertilizer mixed in. My favorite fertilizer is Trifecta Plus from MIGardener. Peppers can take up to 40 days just to sprout, and are slow growers (plant to fruit can be over 100 days easy). But you have a climate where you can likely grow them much longer than most folks. If you have no beets sprouting yet, they're probably duds. MIGardener's seeds have always had high germination rates for me. Baker Creek has been good, too, but I find they're expensive for the amount of seed you get. Take some photos!