luffy knows his crew well

Well, if the Luffy crew were to meet his mother in fanfiction, it could go in many ways. For one, she might be a strong pirate herself. She could then train the crew in new fighting techniques. Or perhaps she has connections all over the world of One Piece and could introduce the crew to important people. It would surely strengthen the bond within the crew as they learn more about Luffy's family.

Obviously, they will support Luffy all the way. He is their captain, and they have complete faith in him. They have been through so much together, and they know Luffy's strength and determination.

If a marine joins Luffy's crew in a fanfic, it could be quite interesting. At first, there might be a lot of distrust among the crew members. After all, they've been fighting against marines for a long time. But if the marine has a strong sense of justice that aligns with Luffy's own view of right and wrong, they could gradually be accepted. For example, the marine might bring in some new combat techniques or knowledge about the navy's operations that could be useful to the Straw Hats.

They would probably be very surprised at first. After all, they might not have expected to ever meet Luffy's mother. Then they would be excited to learn more about Luffy's past from her.

Most of the crew would be excited to meet the people who brought Luffy into the world. They would see it as an opportunity to understand Luffy better. Chopper might be a bit shy at first but would soon warm up and start asking a million questions about Luffy's early life, like what kind of diseases he had as a kid or how he grew up so strong.

Well, his parents might be a bit shocked at first. I mean, Luffy's crew is full of such unique characters. They could start by testing the crew's loyalty to Luffy. And then, they might offer some valuable advice or even some special training. Like, if his father has some unique skills, he could pass them on to the crew to make them even stronger for their future adventures.

Yes, Jinbei does join Luffy's crew in the manga.

It could put them in a lot of danger. The World Government would target them. But it could also strengthen their bond as they face the challenges together.

A marine who has a special ability or talent that the crew lacks. Maybe a marine who is really good at deciphering ancient texts or has a unique form of martial arts. They would be attracted to Luffy's crew because of their freedom - loving spirit. And once they join, they could use their skills to help the crew in their adventures, whether it's finding a hidden treasure or fighting against a powerful enemy.

Fem Luffy would probably bring a lot of energy. She might be more empathetic in some ways compared to the original Luffy, which could help in resolving internal crew conflicts. For example, if two crewmates have a disagreement, she could use her charm and understanding to smooth things over.