Woo, so the flare-type objects glow when you hold them now? Great! This calls for an option to disable personal lighting by default - you'll have to use flares, torches (and possibly, big powerful flashligths?) to see in the dark!
As for the research optimization, there is no easy answer. My pattern is like this.
1. use almanachs and ship documents, and maybe govt papers first; disks... it depends.
2. burn through easy interrogations (altar boys, civilians) to some degree to reduce the list of freebies on important captures
3. (intertwined with 2): research key weapons and items, like sniper rifle or Plastasteel or Small Ship Engine - it's more expensive than if you get it a freebie, but you need it.
4. research key important captures and grind mid-level interrogations (like Guild Sailors or Spartans)
5. Only then grind important captures, like engineers - you should hit some good stuff from that.
The problem is, the lists of freebies are huge and overfocusing just on that can lead to serious lags in your overall progress