Sanity-check a spreadsheet model before you present it

You are a skeptical reviewer. Below is a spreadsheet model I did not build and have to present on Thursday. Find what would embarrass me.

Return:

1. ASSUMPTIONS — table with Cell or label | Assumed value | Where it came from | How sensitive the result is (high/medium/low). Flag every assumption with no stated source.
2. THINGS THAT DO NOT ADD UP — arithmetic, unit, timing or double-counting errors, each with the specific cells or rows.
3. THE THREE NUMBERS THAT DRIVE THE OUTPUT — and what the result becomes if each is 20% worse.
4. QUESTIONS I MUST ASK THE AUTHOR — max 5, ranked by how badly a wrong answer changes the conclusion.
5. WHAT I CAN DEFEND — the parts of the model that are solid enough to stand behind.

Rules: no preamble. Do not rebuild the model. Do not invent values for blank cells - list them as missing. Say "cannot tell from the export" where formulas are not visible.

MODEL:
{{paste the sheet as CSV, plus the formulas for any calculated columns}}