As things stand at present, questions of people who have almost no physics knowledge of their own, who are looking for help in solving a particular problem (homeworky), are mixed up with questions of physics students (university level) up to research level questions on Physics SE, so things have become too messy.
This is probably due to the fact, that two differenc kinds of audiences have developed on this site in the course of time:
On the one hand we have nicely curious people who are not physicists, but who are interested to learn at a rather popular equation free level what physics is about, people who like to find answers to some applied everyday problems from a physics point of view, younger (not yet university level) students who have just started to build up a basic physics knowledge, and people who are looking for help in solving concrete problems they face (homeworky).
On the other hand, there is an audience consisting of university level physics students, academics, and researchers, who like to do physics at a more advanced technical, mathematical, up to research level.
None of these two "subaudiences" seems to be very happy with the present situation since
People more interested in popular, basic Q&A of physics and problem solving, see their questions often closed and not that well recieved
To people more interested in higher level, technical, up to research level questions, the site looks cluttered with too basic posts they are not interested in.
That this is a real issue by now can be seen from relatively recent meta questions such as
Physics SE should emphasis on problem solving
How about a "physics problems" stack exchange?
and most recently this one
What can be done about the (current) ongoing flood of homework and very basic questions overwhelming our site?
So can there, just for Physics SE, something like an internal tag filtered minisite* be implemented, to better structure and improve the perception and experience of the site for both of the two audiences?
That "subaudience", which makes up the larger part of the present overall community, could take the role of the main Physics SE, whereas the smaller "subaudience" could be sent to the internal minisite.
With such an internal minisite implemented into Physics SE, people interested in more technical, higher level Q&A could focus on exactly this without having to dig through a large amount of posts they are not interested in.
At the same time, the criteria on allowed problem (or homework) questions, and the previous knowledge expacted to come here could be relaxed for the other group.
Given that the present overall community is probably not large enough to be splitted into two full SE sites, the minisite approach would in my opinion be the perfect solution to better serve both of the two audiences we now have on Physics SE.
**PS: I am not too sure how such a minisite works technically. Manishearth gave this short explanation of an example: Basically: It's one minisite. Facebook had an agreement with SE that their developers would also help on questions regarding the FB API. With this agreement, SE made a tag-filtered facebook* website, so that FB devs could get their own place. If it works by putting everything with a certain tag on the minisite, it is hopfully not so complicated to implement this?