1.He is good as I am.
2.He is as good as I am.
What is the difference between these two? Do they mean the same? I think 1 means that I'm good and he is also good. 2 means that we both are good and his quantity of goodness is equal to that of mine. Am I thinking right?
You are thinking correctly, but there's a twist: the nuance of being "good" is that it applies to one's nature or character, not one's ability.
Saying "as good as" would usually be understood to address ability; whereas in your first sentence, it is the character of the person in focus.
The natural implications are these:
1.He is good as I am. (We are both good.)
2.He is as good as I am. (We are equally capable.)
Sentence (1) is incorrect. If you wanted it to mean "I'm good and he is also good," you would need to say:
He is good, as am I.
