Almost all of the SH crew had an issue or was against Luffy at first, except Brook I think. Brook was friendly from the jump.
Zoro was on some "get out of here" kind of vibe
Nami was using him
Usopp tried to take advantage of them
Sanji looked down on him kinda
Chopper was shy, but had a bad history with anyone i(including reindeer)
Robin was a full blown enemy
Franky took their money
The only conflict with Brook was his obligation, until he found out it aligned with their adventure
Jinbei was a Warlord and the situation brought him and Luffy together, but in any other situation, Arlong's actions will have to be remembered
Point is, most of these relationships started off shaky, not all though. Any criteria used to predict possible nakama has to be at least as consistent as this.
–- Update From New Post Merge ---
I still have my reservations that Jinbei will join the crew.
I don't think it's a mere coincidence that he's been pushed back so far. It makes sense to leave him out of the arcs since it gives room for other characters to develop and shine. At the same time he's been pushed back so many times that he almost has as much character interaction with the crew as Ace or Sabo, and I think he's better left as an ally in that regard. His inclusion really messes up the 'Monster Trio'.
Which leans into the next potential crewmate….
Monster trio is fan made tho lol. I never understood it honestly. Almost every SH have taken on opponents that 1 of the "Monster trio" would've have ridiculous difficulty beating