@Account Closed Disclosure: I am currently house hacking a duplex so my response will be bias toward that lifestyle.
A couple things you didn't address: Pro for house hacking - appreciation and potentially mortgage interest tax benefit (we'll see come March 2019 if this is still a benefit).
Also, if I understood you correctly, your rent hacking strategy was to find someone else with a rental property that will rent to you and allow you to sublet part of the property, so why would you need 25% down if you aren't purchasing it?
Additionally, while you can BRRR a house hack property, that doesn't mean you have to. I recently bought a duplex that needed minimal work. It currently reduced my rent/mortgage and when I move out and rent the portion I'm living in now will cashflow just fine. If you're comfortable living with roommates you could also do a house hack and rent out any spare bedrooms on the side you're living in to further reduce your mortgage.