Putting all of your money in 1 unit isn't diversified and doesn't provide you an opportunity to mitigate risk. 

But I am familiar with how these gurus generally operate:  make a topic seem complex and dangerous, and in so doing the audience members are thinking, "Oh, no, I can't do this by myself." 

You can mitigate a lot/most of the risk if you really focus on one community. 

That could put me in a dangerous situation where I wouldn't have enough funds to cover it depending on the purchase price.Mike

You are only allowed 1 at a time unless there is a hardship or mitigating circumstances.

Often we can be affected by the sunk cost fallacy because we want to make the time and money "worth it," even if the more profitable and risk-mitigated decision would be to cut losses and move onto the next deal. 

Most molds are not dangerous to one's health and even the dangerous ones tend to worsen already-existing health issues like asthma.3.

As well as number of pets, I'd also break it down further by type and size too (as well as dangerous breeds for dogs or weight requirements if you don't want to specify breed). 1 dog is quite different to 1 hamster, so you might allow 1 dog or cat, or a maximum of 2 hamsters.

Insurance (umbrella policy) is a great way to go for those who are wanting to mitigate personal liability, but the flexibility of financing.

Wholesaling with a license is very dangerous and ethically unsound in a lot of cases.