Is there a specific rule preventing me from taking both Falcon titles in my list? I want to take Chewbacca with the Evade Title and Rey with the SLoop title.

The little dot next to the name says it's unique, the same thing keeping you from "I don't give a f about obstacles" dash with dash crew

Yes, there is. Both titles are Unique cards. You can't have two Unique cards with the same name in your list, even if they do different things. That's why you can't have Darth Vader (pilot) and Darth Vader (crew) in the same list, for example.

See the Rules Reference Guide page nineteen: https://images-cdn.fantasyflightgames.com/filer_public/40/b4/40b44d5f-7a06-406c-ae6e-183c5297e796/swx36_rulesreference.pdf

There are no squads that can have Han/Han, Chewie/Chewie, Lando/Lando, Luke/Luke, Kyle/Kyle, Jan/Jan,... so why would a squad be able to have Falcon/Falcon?

At least in some of the other cases you could have both uniques as part of the same ship were it allowed but having the same "unique" one completely different ships...