I think you are right
Mike and I know that some interpreters have said the same, but the number 6 is also used positivly in revelation:
"And the four beasts had each of them six wings about him; and they were full of eyes within: and they rest not day and night, saying, Holy, holy, holy, Lord God Almighty, which was, and is, and is to come."
(revelation 4, 8)
Therefore I am not sure that it is right to see 6 as an entirely "bad" number in revelation.
As I also tried to point out (perhaps a little clumsy:) the number 6
is found other places in the bibel where it is truly not a "bad" number. On the contrary it is a good number. Such as the six days of creation:
"And God saw every thing that he had made, and, behold, it was very good. And the evening and the morning were the sixth day."
(
Genesis 1, 31)
-Selwyn