I don't know about the first one as I've never actually used them before, but building a second cap (for me online anyways) almost never happens unless my first is destroyed. As part of my starting strat, I actually scuttle the cap factory for a quick boost of credits and crystal, two things I need for my assailants.

Generally, I'd rather have 8 ships that do 15 dmg per second than one ship that does 60 dmg per second. Warfare upgrades also scale way better with more smaller ships.

I tend to disagree, I find that multiple cap ships can kick butt later in the game if you can afford to have them. However, I usually play solo and you HAVE to use a different strategy if your playing online. When online its prob better to go with alot of smaller ships rather than a few big ones. The beauty of this game is that there isnt any formula though, just a bunch of choices.