deshou
 

is it true that deshou has 2 meanings?

1) to signify "probably"
2) to act as question like the "ka" particle

if that's the case am i right to say this:

それで　いい　でしょう? means is it ok with that?
それで　いい　でしょう means with that its probably ok
それで　いい　でしょう でしょう? means is it probably ok with that?

It isn't all that simple but I would say yes to the beginning learner.

First, please use no spacings.

What you stated about the first two sentences isn't incorrect. However, it's not the question mark that makes the first sentence a question. It's the intonation. Note that many Japanese people don't use a question mark. In formal writing, no one does.

Read the first sentence with a rising intonation at its end.

Read the second sentence with a falling intonation at its end.

The third sentence is incorrect. Correct form is: それでいいでしょうか。

if in writing the question mark is not used, how would i know if the "meaning" is the 1st or the 2nd

The context.

As Sashimister said: The context. The same way you know whether "read" sounds like "red" or "reed" in a sentence.

ic, anyway i was wondering if its common if i read japanese and "get" the context wrong, read a few more words then "realised" the context is wrong and backtracked then reread those words with the right context.

do people get mixed up over things like this occasionally?

By "people", do you mean us the native speakers? If so, no.

Rule #1 of language: If a problem over semantic confusion occurs, the language adapts to correct the problem.

ic, hm ok i guess that does sound right