That would be me I guess. Well, things depend on what the node's alert response is. For instance, Sammy's alert response is 'reboot'. So if an alert is triggered, her commlink will reboot, throwing the attacker out (and giving dumpshock if said attacker is using VR). I don't think this node will be doing that, as it's a business node. I think here the response will be 'warn security spider and load some of the programs he or she needs'. In that case, how long you have depends on how long it takes for this person to get in.
I would say the priorities are the following:
-see if they have the file and if they do, copy it, check if they made back-ups somewhere and then wipe it from this location. We can then see about the back-ups. Maybe if they have similar things from other people (it looks like they might), we can get those as well.
-who's inside can always be interesting (camera feed probably)
-and then maybe take out the node to wipe your trail.
As to the initiative, currently MM is the only one running on initiative time. The rest of us is still running on narrative time, waiting for you to do your stuff. In this case it's indeed best to do all your dice rolls at once and then let the GM decide how many he needs and what the results are to save time. This is in fact why a lot of GMs don't like matrix stuff, as it can take a lot of time out game for a few seconds in game. In combat this is less a problem as at that point if you're in the matrix, your running at the same time increments as the rest (you're doing different things, but it's easy to just tuck you into the initiative list and take your action just like the combatters).
So in the future if we're in combat and you're in the matrix, roll them by initiative, but in situations like this, just roll them all at once to speed things up. I do the same thing when I assence multiple people. I just roll as many times as there are people, say to the GM 'I do assensing from left to right, here are the rolls' and then he can do all the results in one post. And don't worry about it, it's something we all had to learn when we started with PbPs.