1) Yes, you will need a FW ATP, since that will be an FAA requirement in Aug 2013.
The new ATP rulers regionals to hire 1500 hour pilots, it does not require that all that time be in airplanes. A few regionals will give partial credit for RW time towards their FW requirements.
Skywest's current policy is to allow 50% of your helo time towards their 1000 min total time, up to 250 hours credit. This means you could get hired with 750 FW + 500 RW = 750+(500/2) = 1000.
I'm not sure how this policy might change when the ATP law goes into effect. Since their effective total-time mins will then be 1500, maybe they will allow more RW credit?