Some questions about player owned builder ships.

[Fenris321]

I'm getting ready to buy a Mammoth Vanguard and I am looking at the various drones it can carry.
Two questions:
1) Do the builder drones actually help the ship to build modules faster?
2) Are the cargo drones necessary? Are they needed to move stuff to and from the build storage?

And another question related to crew. Does a large service crew do anything for the builder?

Thanks,