I cant tell you how many consultations I've had that have literally saved people from thousands of dollars in mistakes because they were trying to do something impossible that some tik-tok scam spouted off in a 30-second clip.

That was my rookie mistake to not vet the actual sponsor better.  

The reality is that the insurance landscape has shifted dramatically in recent years, and underestimating those expenses can be a costly mistake for syndicators and investors alike.Insurance Escalators: A Changing RealityYour point about the outdated assumption of a 3% YOY increase in insurance is spot on.

I feel like it wouldn't be too hard for me to make a 10k-30k mistake on my own in the school of hard knocks. 

Over time of that LL making mistakes he is gaining much knowledge and hopefully it turns to wisdom and eventually he is helping others.  

We've made mistakes along the way, but nothing so detrimental it put it us out of business.

Remember that you can only get one home equity loan per year, you can only have one home equity loan on your home, and you cannot convert your home equity loan into a different type of loan, so choosing the wrong loan can be an expensive mistake that you cannot quickly fix.Time Factors: If you need money quickly, don’t forget the schedule for closing a home equity loan, and make sure you will have time to complete the process, close on the loan, and wait through the cooling off period before you have access to the money.

And someone jumping into this as a complete newbie can expect that they have a decent chance of making some expensive newbie mistakes.

Learn from my mistakes and properly screen your tenants and you should be ok.

Just because you don't make any money on them, doesn't mean you aren't responsible, along with the source of the actual plans, for any mistakes in the plans, or even any mistakes in construction from lack of info, misunderstanding, or just plain stupidity of the builder/user of the plans.