So my question is, has anyone seen how the owner finance space reacts and how it would cope if interest rates were to say reach 10% at the institutional levels?

Turnkey or fixer upper?  

I definitely agree that being desperate for tenants in order to lower your vacancy rate is generally not a good option as the level of uncertainty and potential losses can be huge as it only takes a minority to impact other tenants who are paying good value for money on your rental properties. 

For example, you can buy a fixer upper with the HELOC funds, season it, then refi into traditional mortgage and rent it out.

Your voicemail should focus on how you can help them on an empathy level. 

I have done both of my previous 'house hacks' with my VA and specifically saving it, now that I cashed out of those last two, for a 4-plex when I find an area I want to invest in.The only real downside is VA loan requires a slightly higher level of inspection before closing.

They must understand the qualifications, knowledge level, and ability of potential Equity Partners' ability to make investment decisions.

At your age/income level, you should be 100% focused on learning about investing and aggressively investing your money into liquid assets. 

In my opinion they are all mediocre or worse, although it does give a new buyer a level of comfort.

The link you posted is for township level inspection.