I would not repeat and would recommend an alternative solution primarily because it forces you to be a short-term investor in the stock market which is no better than being a short-term investor in real estate (not a rehabber, but somebody who banks on appreciation/cashflow over 3-6 mos instead of 3-6+ years).If a good property comes along you have to liquidate stocks immediately.  

@Ben Lukes It's partially due to the pandemic, but I also don't like the economics of being so dependent on external forces, such as tourists arriving.

Your mentor should be a friend and someone you trust.You should be able to grow your businesses together.You don't have to join forces either, just have someone to bounce ideas off of when you are having troubles.

So it might be worth it for you to check them out too.May the force be with you ('cuz moving SUCKS!!!

second question: could i force a foreclosure sale on it if i had a lien on the place?

If you're dealing with relatives I'd be cautious about trying to force a deal.  

As in the 1990s the banks thus far are refusing to go along so I'm sure there will be some lawsuits which force the banks to loosen their overlays.  

You can have a tenant move out and wreck the place and force you to do a lengthy eviction.

Goals and business model would affect your decision.Small multi family units often provide mor ebang for your buck (better cash flow for the cost) and you get multiple doors with only one loan.Down side is the exit strategy is usually limited to investors only where as a SFR can be sold to both end users and investors.Multi familys can offer forced apprciation via increasing income and lowering expenses, but SFR's, if bought at the right time in the right place, can offer better appreciation from property value increases.If you want to ultimatley run a landlording business and earn enough cash flow to support you and your family, multis may be the better choice for you.

No one forced you to discuss it with me to start with.