Looks OK to me but:
Be careful of the calf raises, your ankles, back and abs may not like them to begin with. For these and the lunges and squats have a kitchen type chair at your side to give a little support if you wobble or feel pain in the knees.
You have crunches in every day. You might want to change one set of these for a back exercise. You need to work both sides of the body to give good stability and posture and to avoid injury and muscle strain.
The easiest back exercise is to lie flat on your stomach withyour hands under you chin. Keep your toes, ankles and hips in constant contact with the floor. Keep you face absolutely parallel to the floor. Now raise your upper body of the floor and then lower it back to the floor. Done slowly and smoothly. You can leave your hands on the flor for support to begin with building up to raising them too, keeping them touching your chin.
How are you running? Or are you power walking? remember what your granny would say "Don't try to run before you can walk!" Build up to speed, firstly concentrate on distance covered and time spent doing it. Doing more minutes at a slower pace is healthier and safer, more effective (honestly) and - most importantly - more enjoyable!
You might find that every day is too much to start off with. Your body needs a good amount of time to rest and gain the benefit of the exercises, especialy if you haven't done much exercise in the last year or so. So don't feel too bad if you reduce your programme to every other day to start off with!
Low carb or low fat? I personally don't like low carbing at all. Low fat is a good place to start if you haven't tried a diet before or want to do away with calorie counting. Personally, and in my job, we don't use either. Instead we concentrate on a balanced and healthy food intake - a bit like the Balance of Good Health Plate you can find on-line!
As for the gum: Is it sugar free? Why do you chew it? Do you really need it? What could you do instead? You need to reconsider the whole gum thing, it seems a little excessive but you may have a perfectly good reason for doing so!