My advice is to keep the Javelins in drydock for now, and get them refitted; focus our capship crews on Idris Frigates and the yet-to-be-revealed Corvettes; they're both capships, and both deal with roles that the Destroyer is expected to supersede.
Starting small during PU Beta would be a good idea, and getting capship operations ironed out will be a key element in determining whether or not we are ready to field larger capships. Besides, having large crews right off the bat runs the risk of having people mess with our ships while we're in the middle of a fight. (Sabotage is a real issue that may happen.)
So yeah. Keep the Javelins stowed, work on small-scale warfare and asset production, and ramp things up quickly after a week or two from PU launch.