Realizing I didn't know anything about this segment of investing, I picked up a couple books (including Brandon's "The Book on Rental Property Investing") and have been listening through the Bigger Pockets podcasts from the beginning over the past few weeks.

For example, there are three major tenant pool segments in Las Vegas.

And if you service an area "in need" not only does the government look at that favorable (they are the ones that run compliance, etc.) but sometimes those segments are "growing" segments.  

https://www.har.com/content/ne...Houston Real Estate Highlights in November, 2022:-Single-family home sales fell 30.4 percent year-over-year, the eighth consecutive and steepest decline of 2022 as the market endures economic headwinds;-All housing segments experienced negative sales in November.

Wholesalers who are annoying you are doing so, because that behavior is incentivized and rewarded when they find the right market segment. 

As I'm doing my bookkeeping, how should I go about segmenting part of these utilities to the AirBnb business and part of them to my personal finances?

Each segment has different characteristics.

The segment that I (my company) invests in are domain names.

Every property will only attracts a narrow tenant pool segment.

Small towns may rely too much on a single business or market segment.