Man, I never thought about the Oracle thing... that's awesome.

I've used BT very effectively on an Ult. X-men team with Beast and Xavier, they're both great candidates. I've had it work well with Harley Quinn and LE Riddler as well, although Riddler is a litle expensive.

The most effective use I've seen of it required 2 V Richards, one BT isn't enough. Giving everybody on the team plus 2 made a huge difference. Heck it made Johnny and the Thing very dangerous. Even Sue could be lethal.

The best use is on U Atom. I have this as a stock 400 pt. team:
E Hal Jordan GL=125pts.
V Icons Wonder Woman=127pts.
Le Arthur Curry=51pts.
U Atom=50pts.
BT on Atom =20pts.
Fortitude on WW=25pts Total=398pts.

I have Arthur grab an object on turn 1, then get in position for the flying fish man attack on turn 2 with Hal's TK. He does not last long but his 11 atk with 5 or perplexed 6 dam with a heavy for 51 points is great. The Atom's free move ensures he can see most everything and his 20 def keeps him alive throughout the game so the 20 pt. feat is not wasted points.

Use it in high point games. You'll never get your point's worth playing Brilliant tactician in a 300 point game.
I'd suggest trying it in a game of 500 points or more.
There's really no wrong way to give +1 to your entire team.

BT works on characters that share the same TA, not neccessarily Team Symbol. That's why you can use it with WCs like Dr.Doom. I'm just not a fan of the card because it overpoints cheap characters. For example, everytime I play a close game against someone who uses BT, the KOed Tactician's point really come into play.
As I said before, this card is tits in a Faction War, because the combat pump is even cheaper than ICWO.

Rookie Mr. Fantastic doesn't have a team ability, so he doesn't qualify for Brilliant Tactician.

I forgot about the Atom (mostly because I don't have one!), and yes - he is a great Brilliant Tactician. Stealth, free move, 20 defence... he meets all the requirements. I'd be tempted to spend another 5 points to give him Running Start, just to maximise his mobility.

Winning the map roll makes a big difference in how much use you'll get out of a Brilliant Tactician. If you're playing on an indoors map with lots of tight spaces, you may nt be able to draw enough lines of fire, and the 20 points will be wasted.

The short answer is "NO", and I don't believe there is a satisfactory answer "why"....there is some twisted corollary to the reason why Wildcards can "be" Xmen ("cuz the FAQ says so") and why T-Bolts can "be" Titans ("cuz the FAQ says so").

(The long answer is "the powers that be cannot think of a wording that lets them have the rulings they want while preventing the rulings they don't want.")