Yes why not? See this: deogen2.mutaframe.com
Not a droplet of framework. This does not mean that frameworks are bad though. And also maybe I got your question wrong, what do you mean by pure JS? Eventually everything is "pure" js.
Yes you can do it. But before you start your project, very carefully sit with your colleagues and make an estimate about the projects lifespan, turnover of workers, needed features etc. In certain cases vanilla will be better, in certain cases you might go for a framework.