Low to zero down on your first house. 

They accept it as a cost of there decision. 

That ship of low rates that sailed could come back?

You could have just caught the right breeze, or the low rates might have given you a spurt.

While this can maximize leverage and ROI, challenges include getting lender approval for seller financing, high carrying costs, and the pressure of short-term loans.

And hopefullt you won't need a traffic light, which costs in excess of $100,000, though you will be required to do a traffic study. 

I am finding it difficult to find deals due to inaccurate rental projections with high prices and low supply.

What was ABNORMAL were the interest rates for the previous 10-15 years which were unusually low. 2.

Any recommendations for other “low time commitment/ high ROI” marketing ideas? 

Here is your direct quote from the post about low ball offers: "So back to low balling when doing this you’ll get a lot of emails like the one I’m about to show you, this shows that 90-95% of RE agents have no clue how investors do business and they don’t care how investors work, but you as an investor always need to keep your cool and always be the nice guy because you never know that dumb agent might have the best deal one day and if he or she remembers you, you’ll probably get the benefit of the doubt."