In general a reduced research rate and conventional start will make NPR and the other "special" foes more potent for a much longer time.
Reduced survey will also slow down the way you can expand and also help in reducing the slowdown in NPR activating other NPR as well, depending on the values you give the game for that.
Role play in general can very much increase the difficulty rate quite significantly.
For example I always treat industry in a more realistic way so projects have to be set up for long term productivity which means you can't just switch between industrial project any way you want. Most colonies will also want to be as self sufficient as possible over time and will push the local political agenda in that direction, this obviously depend on your role-play theme.
Research can't be easily focused in one area as that is not how research work, so I have several role-play directive in how different research project are initiated and get research facilities handed to them. You also can't easily transfer facilities from one field to another... you can't just turn a large particle accelerator facility into a research facility for tank technology. Also... in the real world allot of technology is highly interrelated in so many ways that progress in one field will lead to progress in other fields indirectly, the game really don't model this at all... so role-play it instead.
A game such as Aurora you should not really care so much about the game mechanic as the story you are trying to tell for yourself. Aurora is meant to tell interesting stories and not to beat...
The next step is playing multiple factions and experience several stories at the same time, not everyone can manage the duality in several stories at the same time but if you do you can experience some epic struggles and challanges.