Visiting Kiev - Safe? Transport? Internet? Cost?

Hi all,

We are visiting Kiev on a business trip soon. Some things that we are interested in knowing:

Do expats tend to hangout in certain areas?
Is a dinner out for two expensive?
    Any restaurant recommendations or place that should be avoided.
Are taxis and public transport safe?
How are internet connections?
We are a mixed race couple. Are there areas we should avoid?

Any other advice would be greatly appreciated.