When I complete the first zerg research mission (Redstone), I have 5 research points to spend, instead of the 3 I am supposed to have. I am trying to play the game as intended, and having these extra points is throwing me off and making it difficult to track
The only mission that could give only 2 zerg research points (added to the 3 you expected) should be Outbreak (Colonists mission 2).
Since it doesn’t make sense (because there’s another 3 zerg research mission before), the logical explanation would be that you played another mission with 3/4 zerg research points before, and missed 1/2 bonus objectives.
Can verify. There seems to be an extra starting 3 Zerg research points before any are collected from the missions.
In one test run, I didn’t collect the 3 points from Redstone and when the laboratory opened up, there were 3 points available.
In another test run, I did collect the 3 points from Redstone and there were 6 points available. (I think the OP didn’t see the 6th point, but it’s there and visible once you pick a research option and the selection UI clears out of the way.)
So now, if we had someone really bored, we could check if failing all bonus objectives in the first 3 missions (before getting the Hyperion and everything), the points would not appear, then try to pinpoint where the points came from if they did not appear.
If they did appear instead, then it would be proof they are 100% free bonus points.
I did that too! That was the third test I did. I made sure to not do any of the bonuses in the 1st three missions and the Zerg research points were still there.