Re:A question about placing blip
We always allow the alien player to look at the blips
My group always played it so that the alien player can look at any of his blips at all times and so know which blips he places and where to place them - he's the "alien commander" after all so isn't it only natural that he knows where his troops are?
Actually I don't see any point playing the game in a different way. For example if you have a mission in which the alien player has one destructor as a sort-of "end-of-level boss" it'd be kind of stupid if the destructor appeared at the beginning of the mission.
An example: in the mission where the marines have to escape from a ship, our alien player placed one destructor and two androids to "secure" the only exit door. Of course none of us marine players knew that until one of us finally discovered it:"Just as I was going to get safely home there are some REALLY bad guys guarding the exit - what are we going to do now? We are all going to die!!!".
Of course it's up to you to play it the way you prefer it, but I personally *STRONGLY* recommend that the alien player can freely look at/arrange any blips before he puts them on the board(s) (and of course secretly look at the already-placed blips just to remind him what is located where). It makes the game play much more exciting, the missions more structured (instead of just killing random monsters you can have a "mission-wide story arc") and I guess also the alien player will enjoy his play much more when he can make more tactical choices ("what monster to place when/where - which types of monsters do what things" etc)