Can a rogue with the Familiar Talent take the Improved Familiar feat and get himself an Imp?
Yes, so long as the rogue was at least an 11th level rogue, then he could get an Imp familiar if he had the Familiar advanced rogue talent, the Improved Familiar feat, and a compatible alignment.
Boo-ya!! Flying, invisible spy for the WIN! Thanks kindly! :)
You may want to check out the Infiltrator and Pilferer archetype for your little friend: lose some abilities you can't use anyway, and gain some very nice skills instead.
If this works would the Rogue meet the "Arcane Spellcaster Level" requirement of Improved Familiar with his effective Wizard level from the Familiar advanced rogue talent, with the caster level from his spell-like ability, or possibly both?