And that is my problem. Given my current educational background and knowledge I cannot differentiate LW between a consistent internal logic and something which is sufficiently based on empirical criticism to provide a firm substantiation of the strong arguments for action that are proclaimed on this site.

I cannot fault this reasoning. From everything I have read in your comments this seems to be the right conclusion for you to make given what you know. Taking the word of a somewhat non-mainstream community would be intellectually reckless. For my part there are some claims on LW that I do not feel I am capable of reaching a strong conclusion on - even accounting for respect for expert opinions.

Now I'm curious, here you have referred to "LW" thinking in general, while we can obviously consider also LW conclusions on specific topics. Of all those positions that LW has a consensus on (and are not nearly universally accepted by all educated people) are there any particular topics for which you are confident of either confirming or denying? For example "cryonics is worth a shot" seems to be far more easy to judge than conclusions about quantum mechanics and decision theory.