If you eat below 1000 calories per day does your metabolism slow down or will it stay raised if you also do exercise and therefore result in weight loss?

I'm pretty sure it will slow down. I've experimented a little bit myself and noticed that you do start feeling fatigued and sleepy and irritably hungry if you eat below 1000 a day. Your heart beat slows itself down and such. I'd keep the calories to 1200.