If you did Nicehash crypto mining in your bedroom, is that considered a "business office" or "home office"? Is either one acceptable?

No, in order to claim a business or home office deduction, the area would have to be used regularly and exclusively for business. Since it is your bedroom, assuming you sleep in it, get dressed in it, etc., it would not qualify as a business or home office. 

So, where do you deduct the electricity costs for crypto mining on your taxes Schedule C if you CAN'T put it under either "business office" or "home office" utility expenses?

You would put it in miscellaneous expense with the description.  Be sure you are prorating it so that you are only deducting the increase in your electric bill from the mining and not your entire electric bill. 

Is that "miscellaneous expense" section you are talking about within the Schedule C where the page says: "Enter Business Expenses Not Yet Reported" and "These include things like postage, internet provider fees, bank charges, and startup costs"? 

This page is still under "Wages & Income" and NOT on "Deductions & Credits" correct?

You are correct.  In the Schedule C section along with Internet Provider fees and yes, all business income and expenses are in the wages and income section, not the deduction and credit section.