Is it possible to take multiple versions of the same unranked talent? For example, in SotB, the Custom Code talent allows you to select one ice or icebreaker to get a benefit. Can I take the talent a second time in order to select another, different ice or icebreaker?
Multiple of the same unranked talent
No. Page 72 of the Core Rulebook:
Most talents can only be purchased once. However, some talents are ranked, which means they can be purchased multiple times."
The talents usually state explicitely that they can be purchased multiple times for different choices .. so basically "it depends".