Some pre-newbie questions

[Arak Koba]

While I anxiously await SE4 Gold to be released (ten days, yay!), I have a few questions for the enlightened of the board:

Is there any value to building masses of small classed combat ships as opposed to just a few large, well equiped ones for your fleets?

Is puting redundant systems such as life support, crew quarters, etc., of any use?

And what does the loss of crew quarters, life support, bridge, do to a ship?