Walkthrough. All Bonus Objectives, Intel.
In this one we start with a Drone Ship, and a few units. Fortunately those few units include a Mastermind.
So, we build our base and strike force (a ton of Tripods and captured Avatars) while dealing with GDI and Nod attacks. In the early stages, our initial units and Mastermind are sufficient to defend the base. After a while we have a buncha Tripods anyway, so defending the base is easy.
After a while, we have large enough force to strike. So we do exactly that!
First we destroy all but the info buildings in the Nod Base. Then we go deal with GDI for the Bonus Objective.
Once that's sorted, we teleport some Assimilators (Scrin Engineers) to the two buildings and capture them, thus completing the mission.