I've given this a bit more thought. If base growth rates are going to stay the way they are now, the Planetology and Genetic Manipulation skills should be rethought. I don't actually understand what Planetology does, so I'll ignore that for now. Genetic Manipulation should be moved down to Tier 1 and/or have it's bonus increased by MUCH more than 4%. As it stands now, 2 days of research for a 4% increase in growth rate is laughable. I might also propose that Researchers get a bonus to these skills above what the other specialties do (much like traders get +10% per rank of Advanced Mineral Collection).

I would also reconsider the "rank" system too. For one thing, I don't know if this has been reported, or I'm imagining it, but I don't think subsequent ranks actually take less time to research than the first one. Also, though, for anything above Tier 3, the time to research is so long, and the per-rank bonus so small, that learning multiple ranks of something in Tier 4+ feels pointless. The game will be over before you get a chance to benefit from all that research. Somehow I feel this needs to be adjusted. I don't know if it's fewer ranks with larger bonuses per rank, or adjusting times downwards, or what, but who is going to get to Rank 9 of Graviton Physics or Super Capital Ships or whatever?