I'm not sure what you mean by visa leniency. If you're here and plan to stay longer than 3 months, you need a visa, regardless of why you're here.
is your husband here for a doctorate program? If so, I think you'd qualify for the family reunification category.
otherwise, the student visa might be the best option.
one thing to consider though, is that all these types of visas expect that you are applying from OUTSIDE the country. It's clearly stated on all the visa information pages.
family reunification:
study:
I have known of several stories involving people living here who weren't on an appropriate visa, and they did run into problems (one foreigner engaged to an Icelander who got stuck in England because he'd overstayed the "free" 3 months by a few days, for example). Personally, I wouldn't gamble with the visa situation and hope for leniency if you intend to stay here.