But many people need to consider if they are financially ready for it or not.

Over time, I’ve accumulated more cash reserves and don’t need as much flexibility, but I’m actually in the middle of a refinance right now using an interest-only mortgage—because the pricing with the lender and the corresponding ARM is more favorable than a comparable principal-and-interest loan.The key with these alternative or "exotic" mortgage types is that you need to be financially savvy and have a solid plan.

Prioritize your financial stability.

Quote from @Jaycee Greene: Financially, I'd only do it if you could convert to a 3x1 AND get at least 50% higher rent.I dont see getting 50% more.

I have a renter in there now and am wondering if a cost-seg makes sense to do financially as I am planning to keep the place for 10+ years. 

im in Orange County CA and there is a huge market here for room by room rentals here. i've been doing this for quite some time (over a decade now), and it certainly has its pro's and cons. my advice if you go about this is make sure you do proper vetting before moving someone in... not only for financials/ credit-worthiness, but also for temperament and expectations in a co-living space. we ask a lot of questions like "how do you handle conflict?"

talk to a competent financial adviser.  

@Steve Englehart Cashing out an IRA or Roth IRA to buy rental properties has significant tax and financial implications.

Also, the whole point of hiring a PM is to handle tenant, maintenance, and rent collection, so if your partner isn’t actively managing but just supervising the PM, IMO not worth having a two people essentially looking over the same tasks.Contributing financially for one person and the other having no financial stake raises decision making questions, such as when to sell, how profits will be distributed, etc.

& how you become financially free is by letting whoever your renting to (I'm guessing that was a step also?)