Matrix stats and when used, Who's computer actually controls the results? Options

[Wandering One]

Okay, now, I know this is going to sound odd but it's the twists and turns that are confusing me, mostly because I'm used to SR2 decking and they've significantly altered the system.

Firewall, System, Response, and Signal. Firewall and Signal are simple enough. It's system and response that's throwing me for a loop, but due to specifics.

You run active programs on your icon, and then invade a node. Now, at first glance, I assume your System is controlling the rating of software that you can run, and the response is handling max # of programs. This seemed simple enough.

Then, later, I get confused in some example and fluff text, where it seems to indicate that the response of the node that the character is currently inhabiting is going to limit the # of programs of both the hacker and the spider he's working against. Also, in the case of IC, if it comes from a different node, is it pushing the response limit of the node itself?

If the node shoots itself in the foot, response wise, doesn't that also affect any hackers trying to get in as well? Also, with say, response 5, am I correct in this: # of programs/result: 4/0, 5/-1, 9/-1, 10/-2?

For system, since in theory you're running your icon on these foreign machines even though you logged in local, is it the foreign system that limits your program rating, or your local?

I'm quite sure I've simply twisted myself up in some details, but if someone could help me untangle this it'd be great.