Number 1 should be yes. Paid abilities is the first thing on the list after approaching, and, following the format for "when encountered" triggered abilities, snitch should occur right before this step.
Number 2, the corp will have to rez and use troubleshooter before the runner encounters the ice, but after approaching it. The runner no longer has the option to jack out at this point, but the corp has to preemptively spend just as he would under normal circumstances against an icebreaker. You can't reactively use troubleshooter to counter the runner's spending.
Reactivity goes beyond saying.
That is pretty much how I saw things.