The Research (2) sticker; have you guys been playing this as "draw an extra research card when doing the research action, but still only keep one" or "draw 2 and keep 2"?
The research rules in the manual say that effects that allow you to draw extra cards still only allow you to keep one. If there was a future rule that changed this, I assume it would specifically say so (ie, 'keep two cards').
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Spoiler (click to reveal)
...or more specifically, there might be a card that says "Research +2" and "When you research, keep 1 extra card." In this case, you would draw three cards and keep two.