Does a hobby business using a personal checking account answer, yes, some, or no in the section, "Is This Qualified Business Income"?

No, in order to take this deduction the income would have to come from a qualified trade or business.  If you are reporting the income as hobby income then you cannot take the deduction.  If you are reporting it as business income, subject to self-employment taxes, then yes it qualifies. 

https://www.irs.gov/newsroom/tax-cuts-and-jobs-act-provision-11011-section-199a-qualified-business-income-deduction-faqs

As an aside, under the new tax law, there is no provision to deduct Hobby expenses. Thus, gross 2018 Hobby income will be taxed.