Logging calories for dummies

My RMR is 1340, according to the Cooper Institute in Dallas where I had this test done on Monday (4/22).

According to all of the calculators I've seen, I need to multiply my RMR by 1.2 to see how many calories I burn in a day, approximately, if I did NOT exercise. That figure is 1608.

Now, say like I burn 300 calories today at the gym. Do I add that figure to the 1608, for a total of 1908, and that would be my 'maintenance'? That's how many calories I'd have to consume in order to maintain my weight?

The way MFP does it is a bit confusing for me. It nets out my exercise calories so I may consume 1400-1500 in a day, but it tells me I consumed around 1000 because it subtracts the calories burned via exercise.

I'm assuming 1000 net calories in a day is a bad thing, right?

I used to think I knew about this stuff but the more I read on these forums, the more confused I get.