Matrix Perception for accessID: Comp 3 + Analyze 2 + Techo 2 + VR 2 (9d6.hits(5)=1)
that is opposed test for targets using stealth
Hacking (4) + Stealth (5) + VR (2) = 11d6 -> buying hits 2
you got nothing, the feeling is basicly like looking at the black hole, the light of information was sucked back
Thread Track: VR Threading (12d6.hits(5)=4)
Turns out threading is intantaneous, it takes no time, Anatomy of a Shadowrun, Runner's Toolkit.
Resisting 4S: VR Threading Resist (12d6.hits(5)=2)
4S overall.
Track: Whats my pool modifiers on this? cos its -(his stealth)
I don't have runners toolkit, so I'll take a leap of faith (learned this phrase yesterday

).
for the trace it is -4 modifier to dicepool (due to his stealth)
also, make an reverse perception test - he is trying to assess if you're running a trace, then access_id
Computer 4 + Analyze 5 + VR 2 ->
11d6.hits(5)=4if he notices (based upon the above roll) that you're running the trace on him, he will be actively redirect your trace by spoofing.
to make it simplier, you have the dicepool of 8 (12 - 4 stealth) - giving you 2 hits on buy, he has Hacking (4) + Spoof (4) which is also 8 DP. Both of you have 3 IP so no difference here. Unless you're willing to spend edge the chances for you to track him are slim. You need to get 10 hits net or more if he is using any anonymizers.
He doesn't react on your tries in any other way than redirecting your trace.