Chemistry: Their lack of seriousness is probably a turn-on. Perhaps they’re spontaneous or perhaps they listen to everything you say without judgment. But your slacker friend may become less charming when you try to do more complicated activities together like plan a trip. So, one way to figure your chemistry out is to have more varied experiences with your partner.
Other than that, though, the chemistry dimension is pretty easy to evaluate here. You either enjoy being around laid-back people or you don’t. So you should probably focus on the character questions.
Character: Does their laid-back nature extend to a lack of responsibility? Do they have trouble keeping appointments and holding onto jobs? Or does their laid-back attitude have less to do with laziness and more to do with having a relaxed mindset?
Next consider the fairness questions. Is being laid-back a cover for letting everybody else do all the work? If they’re a free-loader or a leech, then this is minus points in the fairness character trait. Don’t expect them to make compromises or cater to your needs in a more committed relationship. On the other hand, if being laid-back is their way of letting other people take the spotlight and have a chance to lead, that’s plus points in the fairness category.
Another question to ask is, Are they apathetic about the world around them? Citizenship is a commonly forgotten part of the character dimension, but if you want to eventually start a family, you’ll want a partner who can serve as a role model or who is interested in community activities. On the other hand, they may be very aware of the world or community events, but just choose not to get overly stressed or excited about them.