Removing ability to Edit Budget Methods in the Manage Budget area

Summary:

1. Want to remove budget method switching option
2. Why is the published budget not zeroing out when we switch budget methods?

Content (required):

We are using manager level budgeting. Managers are able to edit budget methods after allocating and publishing budget amounts. I have two questions.

1. Can we remove the ability to edit the budget method in the Manage Budgets area?
2. We had a manager go in and allocate/publish budgets. She then went to edit the budget method from the middle option to the last. She received the warning that her budgets would be overridden. She clicked ok, and expected the budget amounts to zero out. Instead, the distributed amount did not zero out, but went to -140k. If I switch to the middle budget method option, it is -3M. No managers have any budget allocated to them under this leader. Why is the negative value showing and not 0?