Excel Macro Fix and Optimization

I need assistance with an Excel 365 worksheet that has several non-functional macros.

Tasks:
- Delete all macros except for 2 (which I will specify).
- Fix an existing copy and paste macro or delete and re-create it, whichever is more efficient.
- This macro copies a formula from one cell and pastes it into all corresponding cells below it, based on values in another column.
- Ensure a userform, activated by a macro button, works correctly. The userform currently functions as follows:
- It copies a formula from a designated cell.
- Prompts for the corresponding column.
- On clicking "Start," it pastes the formula into all cells below until it reaches "End."

The userform behavior should remain unchanged.

I can provide the Excel file and videos demonstrating the working and non-working macros, including bugs.

Ideal skills and experience:
- Proficient in Excel macros and VBA.
- Experience with Excel 365.
- Ability to troubleshoot and fix macro-related issues.