Hey guys

Im looking for a bit of help... See I have counted calories before, I find it really works for me. However I often eat under my calorie count, as I don't eat large portions. Im really scared of stretching my stomach so that I eat more, so tend to resort to 5 small meals a day! I also have had a history of becoming obsessive and eating too little...so I need to make a plan that I can stick to! Being a naturallly obsessive person, a plan is perfect for me, cas i can stick to them!
As I am 5foot4 I think I should eat about 1500 calories plus exercise to lose. (please tell me if you think otherwise). I want to be able to eat little enough to lose, and but enough to decrease when I plateau.
So basically I aim for:
Breakfast: 350
Snack: 200
Lunch: 350
Snack: 200
Dinner: 400
Im a real creature of habit, I eat a 150 calories breakfast every morning, because this isn't enough I have a Chocolare Milk Drink made with skim milk (about 150 calories). I figure if I plateau I can swap this for black tea.
Lunches involve lots of fruit, salads, sandwiches, yoghurt, nuts and seeds etc.
Because I don't always choose what I eat for dinner, I have budgeted 400 calories for dinner. If or when I start to plateau I can alter my nutrient ratios and be a bit more pedantic about dinner time. If I don't eat enough at dinner, I will supplement it with natural yoghurt!
For exercise - I shall run every morning for 30 minutes. I will build this up over time, increasing speed and/or time. I also weight train, spin, and am considering starting weight training.
Are my calories too low for such vigorous exercise? Will I be able to build muscle eating this much food?
Also if Im losing this much weight, will I plateau? Keep in mind I may continue to lose if I am not happy with the end result!
If you kept reading to the end, thank you very much! hope you guys can help me!