what is the different between ''tip'' and ''tür''
The an interchangeable for the most part. One exception is when you are talking about a species, which must be 'tür' in Turkish :)
I wrote "what type of a book is this" and the 'a' was marked wrong. Does'nt bir mean 'a' ?
I often hear words ending in "r" pronounced as "sh". Am I hearing things?
This is apparently a regional accent (Istanbul??). It can cause problems for Turks speaking English, as they add the "sh" after words like "there" and can be hard to understand.