First of all, are you male or female? If you're male (or a teenager), then a general safe recommendation is that you need to eat at least 1800 calories a day, so you'll need to adjust accordingly. Secondly, why are you aiming at 1500? Did you calculate a number for you or have you picked a number out of thin air? (Calculated numbers tend not to be quite so round- e.g., mine's 1885) You need to find a number that's right for you or else you either might not lose weight or you risk slowing your metabolism.
x2 weetabix with 100ml of milk, fruit salad would be 100g worth of Banana, apple, melon, pineapple, kiwi mixed up. (170 cals). Yogurts I'm looking at low fat ones, haven't decided as to which ones as of yet. (I was looking at muller light ones, is this a good idea?)
Nothing essentially wrong with that (you haven't told me what milk you're having- whole, semi-skim, skim?). I wouldn't find it especially filling though (I tend to need 4 weetabix), and all that fruit might lead to a sugar spike which will make you hungry (ditto the yoghurt). Have you thought about porridge?
Lunch: Chicken Ceasar Salad is 188 calories, Curried Chicken Salad is 227 Calories, Lean ham salad is around 168 calories depending on how lean the ham is. I also thought lean ham with salad in a tortilla wrap which would be 184 calories.
Are these store made or are you making these yourself? What's in them? (particularly that curried chicken- what kind of sauce is it in?) How are they so low calorie? Are they going to be filling? What sauces/ dressings are on them and how might you be able to cut them down? This is where I'd probably eat more to get your calories up- 220 calories is quite a low cal lunch, and I presume if you're out and about that'll give you more of a chance to binge on soemthing if you make yourself hungry.
Dinner: Oven cooked chicken with sweet potato,broccoli, carrots and coliflower will be 296 calories. Honey mustard chicken with rice and veg (peas and sweet corn) Total would be 268 calories.Low fat chili con Carni using lean beef mince. Total calories: 250.
Chicken curry with small portion of rice and veg: I’m looking at doing a homemade paste for this to keep calories down, still currently looking into this though and will update when I find something for this. However chicken will have the skin removed and looking at around 161 calories. Veg will be broccoli (20 calories) and cauliflower (35 calories).
Seems reasonable enough ideas, but again, these are probably very small portions and I bet you'll be hungry (my dinners are sometimes similar to this and they're rarely under 300 calories, usually more like 600). Are you serving them with a grain (rice, pasta, couscous? I think sweet potato counts as a starch, ie a grain, for the purpose of nutrition). And don't go for small portions of veg. Particularly if you steam or boil rather than cook with other methods, vegetables are very low calorie and are a great way to fill up.
What else would you reccomend adding to add the calories up to 1500 per day. Could I add a 4th meal to have at around 9-10? to make my calorie intake up to or close to the 1500 mark.
Eat as much or as little as you like to get to your calorie goal, as long as it's healthy. I'd recommend having bigger meals, personally, although I would leave some room for snacks. Given the calories you're talking about, I know I'd be extremely hungry on this diet and go completely stir crazy.
Snacks i've added things like: Peanut butter and crackers, broth based soups, fresh fruit, boiled egg with one slice of wholemeal toast, fresh fruit, and protein shakes.
Peanut butter and crackers are probably a bad idea (both high in fat, peanut butter nutritionally ok but only in tiny quantities), fruit good, egg good but watch the calories (and how filling you find) the toast), would junk the protein shakes entirely as I don't think you need them. Consider wholemeal rice cakes as an alternative to crackers (low cal, relatively filling).