Pretending is a perception for others, people may think that. That's not something suppose to be proved.
I didn't say betray, leaving the crew is not betraying. Oden didn't betray Whitebeard.
Zoro's bounty was boosted because of being Luffy's swordsman, E.Oda already confirmed Luffy boosts SH pirates bounties, Killer as well wasn't going to be a Worst Gen member and Supernova if Kid didn't boost his bounty. Zoro only fought Crocodile's underling Daz Bones, because Luffy was fighting with Daz Bones's boss Crocodile. Everyone did his job, but only Zoro got a reward because of Luffy again. We literally see why Zoro won that fight;
When Zoro dodged the rocks and survived Daz Bones, he was thinking Luffy and Luffy's crew, again it's Luffy's crew, Luffy is the captain. Because that literally give strength to Zoro, just like it give him strength against Kaku when Kaku talked about Nico Robin.
Without that feeling to protect Luffy's crew as a member of Luffy's crew, Zoro could never improve himself on his own without Luffy's crew, that's because of his ambition to help Luffy and Luffy's crew, not because of his own ambition only. He literally cried to Luffy when he lost to mihawk, again, that gives Zoro strength, Luffy gives him strength. If you didn't understand yet, you are reading the wrong story.
In that scan, Smoker says ''Luffy's swordsman'', that's a different name for Zoro; ''Luffy's swordsman''. Do you understand why he gets a bounty? If he did challenge Daz Bones at somewhere, without being part of Luffy's crew, do you really think Zoro could win, or do you think he would force himself to be better? These are all because of being ''Luffy's swordsman''.
Also as I said, Luffy blackmailed Franky too, what you are saying is nonsense. Except for Brook and Robin, every crewmember didn't want to join Luffy at first, while you are acting like you didn't read the series and pretending like these things never happened with Sanji, Nami etc.