Quick Questions About a Portal Site

Okay, I'm doing a twist I feel should provide great benefits to the owners, and I have a marketing plan somewhat nailed down.

But I just need to ask these 3 quick questions:

1. Would I better focusing on a small segment of my large city, or just go ahead and encompass all of the city. In the first instance, I feel that a lot of businesses could not go in there because they're not in the tight area; and other businesses have different branches around town, in which case they probably would rather be featured all over the city. So, I'm thinking of doing the entire city - what do you think?

2. Should I do a general site that features every kind of business, or focus on a niche such as contractors, restaurants, automotive, ECT? I feel the advantage to a general site would be that people looking for a place to eat might also be interested in something pertaining to autos. Again, I'm not convinced it pays to narrow it down.

3. Should I make it a site that primarily focuses on discounts and coupons, and even include that in the name?

Your opinions please; thanks!