Just my opinions, not RAW.
Battle Awareness:
In my games, Combat Awareness is 10%Act if the players actively look around. If I ask them for the roll, then it's 0%Act. The reasoning is that the skill is also used for %Act remaining after a "surprise" situation. If you are surprised, teleport, ground ripped in two, the maneuver roll is the amount of %Act remaining for the round. It doesn't make sense to penalize you for a roll which might already limit your %Act.
If the player states "Is this guy, bleeding, stunned, getting ready to drop my buddy, sneaking up on the Mage, etc." then that is 10%Act for the PC because they're taking %Act to actively look around.
Using this spell is 10%Act, because it's an instant, but it gives you +25 to Combat Awareness (Situational Awareness, Combat). The spell states specifically that the maneuver is granted and you don't have to declare it as one of your 3 actions for the round. You do only get one spell/round, as normal.
If you cast it when the GM asks for a roll (it is an instant..), then you're getting a +25 bonus, but that's your spell for the round.
"Displacement" and "Mirror image" from "Combat illusions": I wouldn't be against using all of these but I wouldn't let them be cumulative. There are three separate spell effects. I don't think you'd choose. It would be FIFO. First in, first out. The initial spell effect, then the second, third..
Magic item Blade spells has come up before. Different people have success allowing it or not.. Your game may vary.
The Blade spell is similar to a familiar.. a bit. It only gives
you a bonus and really sucks if you ever lose it! For everyone else it provides a
penalty. I'm not against the Blade being magical, already, but I would enforce an RR. Magic Blades in my world would resist any alteration in their effect. Check out Bladerunes.
I'm not against a Blade spell being cast on a rusty piece of crap sword that you find after being imprisoned in the goblin caves for a
month. You've lost your other 'Blade and this is all you can find while busting out of jail. The sword is -10 due to poor upkeep/quality but the spell makes it "a +X magic weapon". This gave more people (here) headaches, if I remember, than anything else.
The same argument can be made that the spell does not stack! The spell makes it "a +X magic weapon". It is no longer what it was and is now.. this. Thus the RR.
Just my take on things.