I would definitely recommend a thermostat - it just saves you having to worry about adjusting the temp when the weather changes (this is especially important in summer when room temp can get to the 30s - the last thing your snake needs is extra heating in that situation!) Our Stimmie hatchling has a hot area of 31-32 with a cool end of about 25.
She goes 8-10 days between feeds (she is on fuzzy mice) she has never had problems with her feeding, but she does get really shy around a shed and will disappear into her hides or under the newspaper for about a week. I hope this helps - but really, I wouldn't worry about it for a while yet!