Eating back calories and MFP preset cal goals

Okay. I have another question that has come to my head after browsing the forums. I put in my goal weight, date to be achieved by and what I want in terms of loss per week (or whatever it is) and MFP first set my cal goal as 1200. I redid the "goal" settings and it upped it to 1260. Now, I generally either don't eat my exercise calories or eat some of them. Now, I also see that some people eat far more calories than 1300. And sometimes stumped weight loss is due to not eating enough calories. NOW, my question. I don't think I could eat more calories than what Ive been allotted, hell, sometimes I cant even eat my goal calories because I'm just not hungry. For instance, I have 350 cals left for today and I'm just not hungry. I don't want to force myself to eat the cals just because MFP says I am "eating too few calories". Ive been losing weight so I don't think this is an issue, but it may turn into one later if I reach a plateau. ... I lost the question I was going for. but I think it runs along the line of am I slowing my metabolism down and making myself reach that plateau faster? I am 5'2", semi active. How does one eat more calories in a day? I just find it mind blowing that I cant even eat 1260 on a day without exercise but others have the ability to eat 1500+ cals and eating back their exercise cals.

Sorry for the bungee jumping in this post... I forgot my initial question. LOL.