1. In more than 99.5% cases, candidates fill out much more than the word limit specified, in the other 0.5% generally it is right on the mark or within 10% of the limit. (Stats are for our clients and for their first drafts).

I feel if you are able to make an extremely strong point in 10 words when you have the space for 20, you are better off than if you struggle even in those 20-22 words. If you feel that a) Your response is extremely strong b) You have nothing more to include, then by all means it's fine. It will be looked at negatively if you haven't been able to convince the adcom in a positive way/strongly even though a lot of space was available.

2. Most if not all schools specify the date upto which work ex. is to be calculated. Please check with the school. Typically, this is upon matriculation i.e. by the time you enroll (again typically Sep 2010 if you are applying this year)

3. Hard to say. Various schools have differing policies. The central tenets that are common include:
1. Excellent communication skills
2. Dressing Sense and etiquettes
3. How much interest you can invoke in the interviewer
4. Clarity of thought
5. Sense of humour/other unique characteristics
6. Leadership quality (you can judge this by speaking to people for sure)

Some schools ask alumni to interview on various parameters such as Would you want to go to school with this guy... Would you hire him... etc.

Hope this adds clarity.

Best,
Ankit
Founder - AppReview