I want to tell the program that a particular investment account cannot be used for expenses until a specific date, or until all other accounts are depleted. How do I do this?

You can tell the program that an investment account cannot be used for expenses until a date in the future. You can also specify that an investment account can only be used after all other investment balances are gone. See the screenshot below. src="https://cdn.livehelpnow.net/clients/21145/kb/useoffunds1_e4f41abe-a82d-406f-a594-2b1cb33c801f.png" id="95d57526-a16d-4dd6-8137-baa550012c94" [...]

Does the program automatically assume that interest payments and dividends are reinvested?

Yes, the program assumes all dividends and interest payments are reinvested in the investment they came from unless the dividends and/or interest are needed to pay for expenses [...]

I want to change the annual return assumption for just one investment account. How do I do this?

You can overwrite the annual return assumption for any investment account. Go to Cash Flow Inputs-->Investment Assets. Select the investment account you want to change. The screenshot below shows where to edit the annual return. src="https://cdn.livehelpnow.net/clients/21145/kb/areturn2_9429a961-bcf0-4ed9-a50a-6e5479d4c134.png" id="3076f673-b20f-47d3-b05e-5cdd639ba1d7" alt="areturn2" [...]

I have an account that is mostly in a regular 401(k), but a portion is in a Roth 401(k). How do I tell the program that a portion of the account is in a Roth?

You can designate the portion of a 401(k) plan that is in a Roth 401(k) as seen in the screenshot below. src="https://cdn.livehelpnow.net/clients/21145/kb/rothp1_9c41a2d0-0b92-4b32-885f-7074cb710385.png" id="d30e299d-c826-4a1b-809d-41f99428e353" alt="rothp1" width="90%" height="auto" data-image="d30e299d-c826-4a1b-809d-41f99428e353 [...]

Where do I change federal and state income tax rates and capital gains tax rates?

The program defaults to calculating federal income tax rates based on taxable income each year. But you can override this with your own average federal income tax rate. You must also enter your average state income tax rate. The program also calculates capital gains tax rates each year and assumes all capital gains tax rates are long-term rates. You can override this with your own rate as well. [...]