James,
When I took the exam recently I asked them to give me a handheld calculator. I think you actually have to ask for it. They will not just automatically give you one, at least not at the ProMetric test center I went to. Just another option if you are concerned about using the mouse with the calculator.
This is tricky question. I used the mouse clicking on the key of the calculator but believe me it is easy and quick. Please do not have this as a concern.
Training for Project Management Professional (PMP)®, PMI Agile Certified Practitioner (PMI-ACP)®, and Certified Associate in Project Management (CAPM)®