I suppose this might depend a bit upon what market(s) you’re looking at for the potential replacement properties but where I’m located investment properties are very scarce right now and when they do become available there’s many people making multiple offers on them which might make it harder for you to land your deals if the market you are looking in is hot.

Depending on the value of the property it may eventually be sold on a tax deed but in the meantime, I believe title would simply remain in their estates or in the last to die's estate.I doubt you'd be able to find a legitimate charitable org to accept a deed from you and your sister without being able to get a title policy otherwise they'll have to job of clearing the title and will still need your assistance. 

The only benefit in this instance, as an investment partner in a JV, or member in a multi-member LLC, is it's an act of "good faith" on my part in the agreement, being extremely transparent about the project's costs for the construction company, and the specific amount the partner/member invoices as profit or salary attributed to construction services on the specific project (I differentiate profit from salary, as it depends on the size of your construction company, a smaller company the profit may be the salary etc). 

Where as a Turnkey rental has some of those same charges but can be rented and be a bit more passive, depending on the route you take. 

Depending on your goals in the next 1,3,5 years will guide you on where and what to invest in. 

This depends on the class of tenant you expect.

Quote from @Ryan Porter: It depends.

Most newer investors will input the numbers to the best of their ability but fail to consider how each input has varying levels of effect on the final return numbers.Experienced investors develop a deep sense of sensitivity and may not even need a model for them to know where the greatest risk points in the project are.

I have done both, it depends on liquid capital available and where my contractors are with other projects.

Hey @Riza Susel, you might want to create a new thread to get a few answers.IMHO, it will depend on where you are going to buy and what your demographic is.We cater to families so we are pretty colorful with lots of comfort.