I'm not used to measuring DME in cups (I use pounds), but I'd think that 1 cup of DME would be about 1/2 lb which would probably make the OG of your starter around 1.080. (1 lb DME in 1 gal water = 1.040)
That's a little high for for my liking... generally I want my starters around 1.040 so as not to strain the yeast or slow them down.
Of course, if 1 cup is actually more like 1/4 lb, then you're right on mark, as far as I'm concerned!
Your pitching temp shouldn't hurt and your starter temp will probably result in a quick fermentation, but you may want cut the temp down a bit to prevent unwanted flavors... especially after pitching the starter into your wort. Unless, of course, you're making a California Common beer
I find a safe area of my house and place a dark towel over the starter. It's easier for me to find a safe place when not looking for a dark place than looking for safe AND dark!