I disagree with the premise that LW tears half-baked ideas to shreds. My experience (which, admittedly is limited to open threads) is that you'll be fine if you're clear that what you're presenting a work in progress, and you don't overreach with your ideas.

By overreach, I mean something like this:

This is an attempt to solve happiness. Several factors, such as health, genetics, and social environment, affect happiness. So happiness = healthgeneticssocial environment.

You can see what's wrong with the post above. It's usually not this blatant, but I see this sort of thing too often, and they are invariably ripped to shreds. On the other hand, something like this:

This is an attempt to solve happiness. First, I'd like to identify the factors that affect happiness. I can think of health, genetics, and social environment. Can we break this down further? Am I missing any important factors?

Probably won't be ripped to shreds. It has it's fair share of problems, so I wouldn't expect an enthusiastic response from the community, but it won't be piled upon either.

Frankly speaking, the first type of post reeks of cargo cult science (big equations, formal style (often badly executed), and references that may or may not help the reader). I'm not too unhappy to see those posts being ripped to shreds.