Discussion boards: https://www.irahelp.com/phpBB
I got a lot of help there when my sister and I inherited IRA accounts from our parents. These are real experts in most cases answering questions, at least back then in the mid 2000's. Haven't visited there in a long time.
I'm 99.9% sure you don't have to worry about RMDs on any kind of IRA, inherited or regular or otherwise, in 2020.
I would think an inherited 401k would have to be rolled over into an inherited IRA. That's just a guess on my part, but seems logical to me.
If it's an inherited IRA, known as a beneficiary distribution account IRA, then you must take RMD distributions every year, no matter what your age (exception: 2020). I've been taking RMDs on my inherited IRAs since I was in my mid-50's. (My sister and I have been over this with many tax and financial advisers). But my parents were over 80 when they passed. It might be different if they had passed before age 70.5 ... maybe I wouldn't have had to begin taking RMDs on it right away in that case, dunno.
I think Roth conversions are a good idea at any age if you expect your tax rate in the future to be the same or higher than it is now. Just don't do a too-big Roth conversion in one year, because the conversion amount is all taxable income, and a big conversion might push you into a higher tax bracket. I'd tell the investment firm, "maybe" if it was me
Edited to add: Full disclosure: I'm not a financial or tax professional. I've read a lot, consulted with tax and financial advisers a lot on these darn IRAs, studied conversion calculators and done a lot of analysis, and as an engineer I know math and spreadsheets, but at the end of the day I'm just another message board rando