@Robocop2020 , assuming that you are US citizen/Resident ( Green Card)/ Resident for tax purposes,
(a) yes you need to recognize the rental income and expenses on Schedule-E and in US$ converted using dollar of the day or published average rates etc.
(b) generally will not ask for proof of the income, expenses or Depreciable Basis of the asset, however it would be good idea to have proof ( in English ) of the FMV at the time of passing of the decedent -- because this will be needed when you dispose of the property ( for gain/ loss computation ). IRS does publish many of its documents / pubs in many languages ( and therefore have access to people who can read/understand quite a few languages, but it is best that you have translation done ( just in case ).
(c) Foreign taxes paid that are eligible for tax credit are generally income taxes on the income. If the taxes that you paid are not based on gross/net income then they may need to be treated differently. Which country are you talking about ? -- there may be treaty conditions that apply
