It might be worthwhile to note the multi dimensional role of this diminutive word as
1. Conjunction:
1. To the same degree or quantity that. Often used as a correlative after so or as: The situation is not as bad as you suggest.
2. In the same manner or way that: Please do as I say.
3. At the same time that; while; I slipped on the ice as I ran home.
4. For the reason that, because: I went to bed early, as I was exhausted.
5. Though: A great actor as he was, he proved a bad model.
6. In accordance with which or with the way in which: The hotel is quite comfortable as such establishments go. The climate is hot in May as everyone knows.
In conjunctional use, you may see the two- verb rule in play mostly.
2. Preposition:
1. in the role, capacity, or function of: I am advising you as a GMAT faculty.
2. In a manner similar to, the same as on the issue of globalization, we all think as one.
Now we may see tht the two-verb rule disappears in a prepositional use, since a noun has to always follow a preposition
In addition, there are adverbial and pronoun uses of as, which are less relevant.(source:the freedictionary.com)
E&OE