Thanks for asking! People don’t ask me questions about this kind of stuff very often, so I’ll try my best. =D
“Queerplatonic” is a term that isn’t exclusively polyamorous — although some polyamorous people have queerplatonic relationships. Basically, “Queerplatonic” is an umbrella term for relationships that are out of the norm in some way (queer) and not romantic in nature (platonic), but still have a very deep emotional element. Very, very different relationships can all fall under the umbrella: some may be sexual, and others not sexual, they can be open relationships or closed relationships, polyamorous or monogamous, a couple relationship or a triad or a quad or any other configuration, and anywhere from dating to a life-long partnership. It’s a fluid term.
The word was invented as a way for asexuals and aromantics to describe their relationships, but anyone can use it! If you want more information, read this post, and check out these two blogs (fuckyeahqueerplatoniczucchinis, qpadvice). You can direct other questions to those blogs, or find some people in queerplatonic relationships and ask them how they do it! I’m not currently in a queerplatonic relationship, so I might not be the best representative.
You also asked about the polyamorous lifestyle. “Polyamory” is another umbrella term. The basic core of polyamory is honest, open communication, and the consent of all people involved. Everyone does polyamory differently. Some people describe themselves as ethical sluts. Some people have open relationships, and others closed. Some poly people are single, or coupled, or in a triad, quad, V, polycule, tribe, or a wealth of other configurations. Some rank their partners by importance (primary, secondary, tertiary) and others don’t. Some people have multiple sexual relationships, or multiple romantic relationships, or sensual relationships, or queerplatonic relationships — any combination, really. Polyamory is what you make it. =)
Check out other blogs if your interested. This one is good, and I follow around 40 other poly people on Tumblr. If you want some blogs to follow, or have more questions, hit me up. ^^