Personally, i believe there is no real problem with using a locator agent on an alt, or having someone else run them for you. 'friend of a friend' and all that.
This. It's one thing for an alt to go do the locator-agenting for the main (or another alt) if you're too lazy to go there yourself and do it, because you can always fudge any IC interactions behind the scenes later if it comes up. For example, Morwen and Naoko have access to similar locator agents. Morwen can't fly in highsec, but Naoko can access those locators for her. So, either Morwen asks Naoko to do a check for her, or I can theoretically fudge something with Morwen going in person given her habit of running around on foot. As I generally don't use locators, I haven't really had to worry about this sort of thing on a personal level yet.
The issue that brought this up, Nikita, was that you wanted something done IC, but out of a combination of alt-lacking-skills, laziness and/or time constraints, you went around asking people OOC - specifically asking people who would, bluntly, not want to perform this service for a Cartel loyalist.
If you wanted it done IC, you should have contacted people IC, or at least talked OOC with people who have characters who would have been open to prodding one of their locator agents for Nikita.