On some cards (big convoi) is an earth symbol. I went through every card and couldn't find something that corresponds to that symbol. What does that symbol mean?
It is an Earth tag, there are a number of cards that refer to the tag, for example giving a discount when you play a card with the tag. As an example the corporation Terractor gets a 3M€ discount when play such a card
If there is an o2 condition on a card ( eg the one with the bear) that says x o2 required, does it mean exactly or also above? The text on the card only says "o2 must be x". I guess also above, but I'm not sure.
Unless the value is specified as a maximum, it means at least that value, so above also counts.