Wow that is a loaded question. You really need to speak to your lawyer.
This information does not constitute am attorney / client relationship and is just a general answer to the question posed with the limited facts available. There is no substitute to a consultation with an attorney licensed in your State.
All of your questions should be answered by your trial counsel. If you were dissatisfied with his/her performance to that point or for any other reason would not be using the same attorney for an appeal then you need to engage the services of new counsel who will answer these questions.
I have rarely to never seen a situation where a sentence was negotiated based on a waiver of appeal.
Law Office of David D. White, PLLC
1205 Rio Grande St.
Austin, TX 78701