As /u/JoshuaSonOfNun points out, the Bible isn't one book, and this makes your questions endlessly complex.

It's a collection of 66, plus or minus depending on stream of Christianity, books. Each book then can be considered under its own heading:

1. What was the date of earliest composition?
2. What other elements may/may not have been added to that earliest composition, to form a composite text (for some books)?
3. What was the date of last revision? (Actually not a real question because of the nature of text transmission) - prior to more-or-less being standardised.
4. What was the earliest date a version mostly resembling our modern versions was produced and circulated?
5. What is the earliest manuscript containing a portion of this text? (Usually considerably later than all the above).
6. What is the earliest manuscript containing a complete version of this text?
7. What are the earliest collections of some of these texts?
8. What is the earliest collection of all these texts?

Then you can talk about what has been 'altered/changed/added' at the level of individual passages.

My point is to make clear how complex a set of questions this is overall. You're essentially asking about a whole field of scholarship. Scholars write whole books on, say, the history of a particular passage.

So, not that these aren't interesting and important questions, but they are, as a whole, beyond what you can answer in an /r/AskHistorians post. 4.