Do you think its advisable to have bullet points in your essays?
Business schools want to see how well you can put word to paper, not use writing crutches. Bullet points are frowned upon in the essays. The structure of the essays should be formal, while the tone may deviate slighly from formal conventions (you don't want to sound like you have a stick up your rear).
Also, in your essays - should you mention numbers or rather write them - eg. 2 examples to illustrate or two examples to illustrate?
You should use correct grammar, which involves spelling out single-digit whole numbers--in this case, you would write "two." This probably seems anal, but the schools do care. Writing correctly probably will not count for much, but writing incorrectly will count against you.