Because dual agency is an impossibility (I’m a lawyer) and if I want to see one property I don’t want to be tied to an agent simply because I wanted to see a different property.The listing agent’s fiduciary duty to his seller client should be sufficient for the listing agent to just do a no agency showing agreement with the potential buyer.

It's not impossible, but I think you're already making a mistake by deciding you don't want to work with experts.

Consider FHA loans for lower down payments, but remember, the key is to find properties where the rental income covers your mortgage and expenses, ensuring positive cash flow (although in Austin is will be hard, but not impossible, to accomplish)Aiming for five properties in five years is very ambitious but achievable with the right strategy.

My friend tried to comply but the age of the property makes it impossible to get the property up to code other than demolishing and rebuilding the whole property.

Unless you have a solid net worth or strong track record in this area, it will be tough, but not impossible.

But it's been for too long and it seems impossible for them to turn the situation around.

This is far from impossible and many people have a lot of success managing their own STR, but it sounds more involved than what you're looking for.

If scaling is truly impossible and you hit a ceiling at $80000-$90000 a year (figure I have got by googling "How much wholesalers make"), then it's indeed kind of a dead end a job with only benefit of working remote and making your own schedule, away from corporate world and office politics/nonsense.

If your goals change because you learn that 15% is impossible in the market you want to be, that's perfectly normal and you can decide whether to adjust your goals or to change markets. 

Some years it may be $0, and some years it may be 20%... its impossible to know for sure.