Is it odd that I occasionally dream in text?
Yes, it's very odd, because while sleeping the part of the brain which is used for words is deactivated.
You can't read or write in dreams.
You can of course "dream that you write" or "dream that you read", but you can't actually read what's written.
Sometime when you remember your dreams, and there were some reading/writting behavior, try remembering what was written physically and read it again. You shouldn't be able to do it.
Text is just some visual signs too, but it's strange that you can picture an object's form, but not a letter's form.
About thinking in which language:
I'm native French, and I often think in english
But there are two way of "thinking".
I can "talk the words in my heads like if I were speaking to myself out loud"
and I can "imagine the situation that I want to do without thinking with any word". I can just know what I want, what I desire or need to do.
About what Densetsu said, while not remembering the used language, I think it's not totally the same thing as thinking with pictures.
it's more not caring which language you used to understand a situation.
sometime I read some text and only after few lines I realize which language I'm reading. I don't make any difference when reading French or English, I understand the meaning automatically without the need to translate.
I think you remember talking about that subject, but you didn't care which language you used, it was natural in either ones.
I think meanings or symbols is more appropriate than "visually imagining".
like you said, blind people might not used image, but they know what they want, their ideas (like eating when hungry).
I think Japanese language is even more used in symbols than western languages, like watashi is used for everything referring you yourself and not to the word "I" or "me", kagami for everything that reflect and not to the object "mirror" or the word "reflection".
(sorry, the post may be a little mixed with different ideas)