Try this answer here for the first part:

http://paleohacks.com/questions/18463/how-many-grams-of-carbs-keep-the-average-person-out-of-ketosis

Of course, the only way to be sure is to eat more carbs if you're unhappy with your breath.

Regarding your second question, I think you'll see little difference. You'll probably feel happier on the run and it would arguably be more synergistic to concentrate your carbs on exercise days, but for the level of intensity you are talking about it won't make much difference to your progress or recovery. I would suggest eating freely after (and before) your activity so as to be happy with that, and then adjust what you eat the rest of the time to balance it out. But your body should be able to cope either way.

Jennifer, there is no specific amount of carbs that determines that for everyone. There are others who can explain how it all works. Here is a quick answer, which I hope will help some. :)

The amount of glycogen stored in the liver, and what the pancreas and beta cells are up to is different in each person, for example.

Dr. Wolfgang Lutz recommends 72 grams of carbs per day, to stay out of ketosis.

Dr. Jan Kwasniewski's plan has carbs at plus or minus 10 percent of your ideal Kg weight, which is determined by height in cm. The following is excerpted from this link.

In order to work out the correct daily food intake using this proportion, one has to know how many grams of protein needs to be ingested in a day to satisfy body's requirements. This amount varies from person to person and depends on a "due body weight". Due body weight, in kilograms, is equal to person's height in centimetres less 100 (± 10%). Thus, for a person 160 cm tall, a due body weight is 60 kg ± 6 kg.

A correct amount of protein to be consumed in a day is approx. 1 g per 1 kilogram of a due body weight. Thus, a 60 kg person needs to consume 60 ± 6 g of protein to satisfy body's daily needs. Any excess of protein, above the daily requirement, is converted by the body to fat, provided energy requirements are met by other components. Having worked out the amount of protein, one can then calculate the amount of other components in a daily menu. Thus, for our typical 60 kg person, the consumption of 60 g of protein has to be accompanied by between 150 to 210 g of fat, and 30 to 50 g of carbohydrate in order to follow the principles of the Optimal Diet.

Usually it's around 100 grams of carbs/equivalent as a starting point. The thing to remember is the equivalent part. Protein converts at around 58% efficiency to glucose in the body. So you can eat low carbs, but still knock yourself out of ketosis by taking in a lot of protein.