Exact match will most likely bring in less clicks as the targeting is very specific unless of course your keyword is auto insurance for instance. Less clicks in not necessarily a bad thing as exact matching will qualify your visitors better.

It completely depends on your business and how you setup your campaigns. What type of business do you have?

In general, you should start with broad, phrase, AND exact and have negatives as well, and make sure to track conversions. Generally speaking, phrase and exact do tend to convert better than broad, but not always... and sometimes you lose valuable search volume by excluding broad. Just be sure to use negatives if you use broad.

Both can work for you but certainly depends on your business. Exact match may give you best ROI and then phrase match.

i think that the best option is broad match because it is able to provide you all the combination of the word with any word phrase..

Then phrase match and least one is exact match..

but these all category are depends only on the particular keyword.
If you think your keywords are very generic and you are getting targeted keywords through that or your conversion rate is not upto the mark ..then you should move to another match

Why do you recommend to measure negatives? Im curious.

Ah, interesting. I came across something similar some time back.

High Risk Merchant Account

I think you should target Broad Match.

You can use the broad and exact match in your pay per click . And test what would be the best result