Broadcasting - EMail Bursting

Hi,

Can any one please answer below questions on email bursting.

1. Lets say our Vendor master data consists of 50000 vendors,If i opted to broadcast a report based on email bursting,Does it shoots email to all the 50,000 vendors or only vendors for which transaction data exists during report execution period.
2. We have few issue when we scheduled broadcasts manually,When we triggered multiple broadcasts at same time our pre calculation server is out of resources and broadcasts are failing.If i opt for email bursting will the system shoots email all the vendors at the same time.
3. When we broadcast email to vendor our requirement to broadcast output to 2 email (one vendor email and the other is internal email which will be constant at all times for records)...my understanding is with email bursting we can send email to a single email id...how can i address this issue.

Sorry for 2 many questions,But unfortunately i never worked on email bursting.

Thanks for your time.