Sprites and Hacking, Am I thinking along the right lines? Options

[Aerospider]

So I have a nytemare dissonant technomancer who's decided to pick on the street samurai and as a first assault will be sending a registered chaos sprite (Rating 4) into his commlink to mess him around a bit. He's not a very experienced player so he's not employed any special defenses (beyond a purge program) and his firewall's already been chewed up (Rating 1) by a virus so it should be pretty easy.

Here's how I think it might go:

First, the sprite probes the target rolling Hacking + Exploit = Rating + Rating = 8 at a threshold of System + Firewall + Admin account = 3 + 1 + 6 = 10. With the DP dropping at each interval that should take in the region of five hours (rather than days since sprites work in VR). The technomancer could do the probing herself, but let's say she has reasons not to.

When the sprite is ready to log on the commlink gets a single Analyse + Firewall (Sprite's Stealth) roll to flag the intrusion, which it automatically achieves because chaos sprites don't have the Stealth complex form.

The sprite has two more IPs that round. With one it starts up its Distortion power (-Rating to all Matrix tests in the node). With the last IP it maintains the distortion (simple action) and transfers the samurai's address book to the technomancer.

At the end of the turn the node issues a restricted alert, informing the samurai that someone's intruding on the node. If I'm feeling generous I would say that the commlink had a default ARC of terminate connection which would be System + Firewall + Alert bonus - Distortion = 3 + 1 + 4 - 4 = 4 against the sprite's Hacking + Exploit + Admin account - Distortion = 4 + 4 + 4 - 4 = 8. If I'm not feeling generous it does nothing against the sprite. Either way, assume the sprite is unaffected.

On the next turn the sprite goes first, maintaining its Distortion power and transferring the samurai's bank details. The samurai, in his AR display, sees his node being warped and the harrowing thing that's tearing it up. He initiates a reboot, correctly assuming that he is nothing but a sitting duck. He also gets to diminish the Distortion power (no action required) with System + Response = 3 + 3 = 6 so assume he gets the -4 down to -2.

The reboot is System + Response - Distortion = 3 + 3 - 2 = 4 dice per turn to achieve a threshold of 10 (no reduction in DP over time). That's 7 or 8 turns for the sprite to do whatever it likes, including reinitiating the Distortion power and prolonging the shutdown.

As the IPs go by the sprite would start really screwing things up, including deletion of programs (particularly Analyse so he can't get its access ID) and deletion of the access log.

How does that read?

Any thoughts and suggestions on my interpretation of RAW and the actions of the sprite and samurai would be much appreciated.

NB – as the player is relatively new to SR4 and as the dissonant is part of a longer-running plot I won't really be doing very much to his 'link/PAN on this first encounter, but I do want to inspire a sense of threat and persecution.