Questions about probate, opinions are welcome.

[spqrzilla]

This does not make a lot of sense. First of all, you said you "filed" a will with Douglas County. Why? Where?
Secondly, 401K accounts should have a beneficiary. Did she not supply a beneficiary?

If there is no beneficiary, and you have not yet opened a probate, and the estate has no real estate and is less than approx $65,000 then it is illegal for Home Depot 401K administrator not to accept a small estate affidavit. Under CRS 15-12-1202(3) They are liable for all attorney's fees and costs required to obtain an order to compel them. Tell them your attorney charges $300 / hour for this kind of work.

If you decide to open a probate, the difference between "Formal" and "Informal" is whether or not a Judge is required to exercise discretion to make a decision on accepting a will into probate and appointing a PR. So long as there is no question of the validity of the will (ie., its not a copy, its not holographic, etc.) and there is no dispute over the choice of PR, then the probate can be opened informally. Informal means that a court clerk called "Registrar" will actually sign the order and Letters Testamentary.

Note that this is completely separate from whether or not administration is supervised (ie., court approval is required for every action).

If you need more, message me for a phone number and I'll talk to you.