Hi Kyle,
There are a few enhancement requests logged with Product Management that revolve around this. Being able to copy paste emails into a large text area was one that was eventually implemented. I believe the next enhancement would likely start with shared lists (contact groups) over segments, because they won't contain dynamic criteria.
In general however, Sales users should have the Marketer team execute large personalized sends using signature rules and signature layouts for the same effect. The primary use case for Engage is to provide Sales users the ability to leverage Eloqua content and tracking.
Regards,
Bojan