Because I'm a Rogue.

[Oric the Thief]

So I'm stating this first, I have no interest in getting spoilers for this adventure path, as such I have not read any of the other posts. I am the Rogue of an adventuring group going through the Rise of the Runelords.

We are about to go into Magnimar, where in character backstory, my Rogue has passed through and stayed around for about a year. This is where he learned the tricks and trades of the art of stealing, lockpicking, and pickpocketing.

The key thing I wanted to know, as my GM knows all of this, what would be good places to "acquire" money/loot from that won't hinder/effect the plot or key important people. Or would it be better to just steal indiscriminately from non-named NPCs?

[Misroi]

Honestly, everyone you steal from have the potential to become "key important people." It's up to your GM to decide how they react to your thefts. Also, if you spent a year in Magnimar plying the cross-trade, then you made some contacts, probably on both sides of the law. Has he mentioned anything about that?

[Latrecis]

We cannot answer this question. There are only three types of possible NPC's.
1. NPC's defined/described in the AP itself. Obviously we cannot discuss those since that would be a spoiler and even if we could, by definition they are potentially important to the story.
2. NPC's defined/described in the Magnimar Sourcebook. We can't reference those either since we have no idea whether your GM owns or intends to use it. Nor do we know how he/she might be planning to plot the Magnimar portion of the AP so anyone of these NPC's could also be important.
3. NPC's developed by your GM. Obviously we don't know anything about those.

Please take this line of inquiry up with your GM.