I don't like any kind of security alert before we strike. That just sends all the security on their toes and we don't need that. The most surprise possible is best and that means NO prior warnings ANYWHERE. I'm also a bit wary on committing to fire support unless necessary. We are your cover no your distraction. Once the security engages us, things are automatically messy. If you can with our silent help better set up to strike, by all means, direct us, but anything that gives away our current advantages of surprise and brief fire superiority. If you can get the other mages to help you do the strike, by all means, go for it. (I'm just not willing to count on it.) That would actually be a great thing for us, because they'd automatically be thought to be traitors and then a security priority! add to the confusion with other distractions via Das, and with the rest of our group be ready, flexible, and surprising once things do need to happen. Cast the spells you need, summon the spirits you've got to summon, and we'll be here on the roof ready to back you up IF things go south.
(though reading the IC I guess my thoughts are coming in a little on the late end. If we're already committed to another plan or actions are already in play we can just roll with it.)