@mrj224 @ClinTEastwooD @Someanon While they may have appeared suspicious at first, I think this chapter has given several different reasons to believe that they are just the nice, trustworthy, friendly people that they seem to be.
1) They have a stellar reputation among a guild with multiple branches, and are known to the guildmaster, so that would indicate that they have been successfully completing missions.
2) We are told that Gareed made mistakes when he was younger, was given another shot, and learned from those mistakes. This comes from a few different sources, that didn't just back up what others were saying. The ability to learn and mature from past mistakes is primarily associated with good people, while bad people learn how to hide their mistakes, or blame others for their failures.
3) This is the biggest one for me. The way they handled the two immature adventurers. They recognized that, if the truth came out, it would be likely that they would be kicked out, and not able to progress further. They also recognized why the two were trying to do what they did, and that they had good motives, overall for doing so, but ended up way over their heads. They recognized the potential for the future in the pair, and decided that they would do what they could to make sure they had another chance, having confidence that the two would take advantage of it to improve themselves, and not make the same mistake again. The showing of grace, compassion, and understanding are traits that are mainly associated with good guys, especially to this degree.
The guildmaster seems to know exactly what happened, but also wants to make sure that they have another chance, so he asks them to confirm in a way that makes them feel like they have to cover for the party that helped them, rather than just their own necks on the line, because he doesn't want to waste their chance at redemption.
I think this party had rough beginnings, but others saw their potential, and encouraged them, allowing them to become such great adventurers. As a result, they are good at seeing the potential in others, and want to guide, encourage, and protect them, to pass on the favor that they have been shown. Unfortunately, they are viewed as being suspicious because we are used to people trying to use others, and not show kindness for the sake of kindness.
It is still possible this group will end up bad, but I'd be very surprised, especially based on this chapter, and also disappointed. Manga (and real life, more) needs more people that are kind for the sake of kindness, even if there isn't anything for them to personally gain from it.