Families are useful in this situation. Use three families "enemy", "friendly" and a third family like "Blue" that includes both the "enemy" and "friendly" families.
If you pick a single "Blue" instance you can find if the instance is in "enemy" or "friendly" with:
+ Enemy: Unique ID is Blue.UID
or
+ Friendly: Unique ID is Blue.UID
In the same way, you can find if the instance is a particular object type with:
+ Sprite: Unique ID is Blue.UID
For turns based on a character's speed, a way to do it is for each object to have a variable that increases with the character's speed stat. When the variable reaches a certain value the character is given a number to queue it, the first will get 1, the second 2 and so on. Then each character is picked by that number for the corresponding turn, and at the end of the turn they will start the process over.
Hope that makes some sense, I tend to be not very good with explanations sometimes.
Here is an example that shows some of these ideas:
http://dl.dropbox.com/u/5426011/examples6/turnBased.cap
Feel free to use it however you like.