Agents, assist, and teamwork tests, Confusing myself again Options

[suoq]

Caveat: Missions, Season 4.

Creating a new hacker and thinking about giving him an agent sidekick, which makes me realize that I've avoided agents on the grounds that hacking already gives me a headache and that's one more complication. On the other hand, I like the idea of a sidekick, complete with advantages and disadvantages.

Configuration 1: Agent, rating 3, is loaded into the hacking commlink (complete with Response 6, System 6 requiring 10 points of restricted Gear. ouch.) with access to rating 6 programs.
Configuration 2: Agent, rating 3, is loaded into his own commlink (Response 5, System 5) with access to rating 3 programs. (I like to think of him as "Tonto".)

Now I've never sorted out how agents actually work with regards to teamwork tests before. I'm assuming the agent rolls it's rating, plus the software's rating, no hot sim or anything like that. and I'm assuming those hits are additional dice I can add to my roll. So in Config 1, I'd get, on average, 3 more dice, and on config 2, 2 more dice.

On config run, all trace attempts come back to me. On config 2, the target has to decide which one to trace, me or the agent. Is that correct?

In configuration 1, if both of us are using Exploit, does that mean I have 2 instances of exploit running for performance purposes although I only have to purchase 1? And if they're ergonomic, are both of them ergonomic, with the limitations of the number of ergonomic programs that can be run?

In configuration 2, if I want the agent to work on his own (instead of assisting me, searching for hidden nodes for example), can he use the software on my commlink?

Anything else people with experience with agents can think of that I missed?