Good subject first of all.

I do not prefer fast setting games, not because I do not want a short game but because there is less likelyhood you will fight with the various technology steps but again it is a preference.

However in the spirit of your example:

I would ask is an average turn length of 1 minute long enough in particular with fast settings where you will have to be redesigning your ships to update them.

The rest of your suggestions seem to be good for the scenario you are aiming for.