Any way of merging projects by copying timeline data from one project into another?

Yes. Open Vegas TWICE - once for each project. Now copy what you want and paste it into the other.

Of course, you could always just drag the VEG file to the timeline of the other project (see "Project Nesting" in the help file)

Yes, you can copy tracks over from one Vegas to another Vegas. But When I did that, it didn't bring the fx and key frames. I did manually copy fx and key frames to each track, took a little time, but its OK!....
Im sure there is a settings for that. But i dont use that often...
Re think about nesting. You will render your project out much slower when using nesting. But if you are not stressed.... Sure nesting is a great way to do it on to...

Yes. Open Vegas TWICE - once for each project. Now copy what you want and paste it into the other.

Of course, you could always just drag the VEG file to the timeline of the other project (see "Project Nesting" in the help file)

Does this mess up keyframes/FX at all?

Does this mess up keyframes/FX at all?

Not if you nest veg files....
Vegas reads ALL the data in the veg file, like grouping them...