In some instance a bad investment can be salvaged by changing strategy.

If you're willing and able, I do recommend the "house hacking" strategy which is just a fancy name for buying a rental property and living in one of the units, because you'll get very favorable financing - an owner-occupied fixed-rate 30-year mortgage.I'd also say, analyze that property as if you won't live there and it's a pure rental, and make sure the property is still cash flow positive if there's a tenant in your unit because then you'll know if it's actually a good investment.And when you analyze it, include payment of a property manager in your #s because if you don't, and doing so would make it go cash flow negative, then you've just bought yourself a job because you literally can't step away from managing it without losing money.

How does acquiring compare to renting a small office or sharing office space with another business in that market?

Your new place should turn into your new business location as well. 

The best strategy really depends on your goals, risk tolerance, and your market conditions.

Beg family and friends to fund it for you.They "might" do it if they see you've learned a lot and your business plan sounds very solid.How do I know this "might" work?

While personal loss is difficult and understandable, running a business that directly impacts property owners requires a contingency plan.

My preferred options are:1. house-hack with a duplex under ARV; live in one unit => renovate => rent the other unit2. buy a SFH under ARV that could be converted into a duplex (preferably adjacent units vs top/bottom) - I'm assuming the biggest challenge with this strategy would be separating the infrastructure for utilities; and costly.

It's more important than doing individual property analysis, because when you do a proper market analysis, you are analyzing ALL of the properties in any market(s) at the same time.Now, one of the analysis "pitfalls" is not understanding what defines a market, or more importantly, a Micro-market.Another problem is focusing on one strategy, and trying to fit each market/property. 

My passion is to help other active investors shift their strategy as I have.