For instance someone bids up to $400k, but has a 7 day close and all cash, no contingencies...and you have bid $1,000 over 2nd best to get to $401k, but you have a home inspection, financing, inspection contingencies and a 30 day close.

For instance, I bought my first condo there in 2016 for 260K and now it is worth about 420K.If you are looking for a good realtor in the tricities, I can recommend Krista Lapp with Royal LePage.  

For instance I buy Duplexes for 30k, put another 25k into them, and I am all in with the cost of money and closing at 60k. 

For instance, this cash buyer doesn’t CARE about your fee.

For instance, if you have hard money to back you up in the event that your conventional mortgage isn't ready on time, you could potentially waive the mortgage contingency.If you were confident enough in the home's condition, you could waive the home inspection.Both of these carry very real risks, but if you think you can handle them, you can submit a very strong offer - much stronger than an offer at a higher price that has those contingencies in it.

Being new to the REI world, everything I'v read in my research on investment shows instances of people buying 9% cap rates or higher.

Mortgages at 70% LTV are incredibly safe in most instances. 

For instance, if you're doing a replumb of a bathroom, you'll need to get a licensed plumber to pull the permit from the city.

Yes - there may be an instance if the distribution is above the partner's basis - that he may need to report additional income.

In your example for instance it doesn't work because you need both purchases (and probably one more) in the 1031so you can meet the reinvestment requirements.