If you sell a property, and do a 1031 exchange with the proceeds, but don't need all the proceeds for the down payment of the next property, are you taxed on the additional profit that isn't part of the exchange?

This initial negative equity position consumes the initial cash flow.  2) the addition of the adu makes the property multi family and likely makes rent control apply.  

I know in residential lending you can get a HELOC to borrow a down payment to buy another property. Does this exist in the commercial realm? Current value of paid off property is roughly 350k , looking to borrow 75k-1...

In most single family zoned areas adding a single ADU is not a value add meaning it will not add more value than the hands off cost of the addition.  

BP has built a great selection, all of them worth reading and that will help you build foundational knowledge.To answer this one: the words from old school investor Dolf De Roos "seldom sell" and you will find a lot of post on BP from people who regret selling properties in the past.

In general, an additional insured is added when the additional party carries some of the risk related to the insured property."  

The cons as i see it include loosing the 2 of 5 year cap gain exception, typically not an ideal rental because the emphasis at purchase was buying a good home for your family and not a rental with optimal return (my ex-home consistently has the lowest cash flow for equity in my RE portfolio), not disconnected enough from the property causes addition angst on damage and may result in over improvement.  

Additionally, the property includes an outdoor swimming pool.The use of the accelerated depreciation strategy helps real estate investors to reduce the tax liability immediately which therefore increases their bottom line due to the offsetting of income.

The credit thing should not be an issue for many DSCR folks like myself. 80% ltv may be an option, but,I have seldom found the tradeoff in cost/rate to be worth it in the last 12 months. 0% origination is possible, but, as others have said compensation is received in one fashion or another (higher rate, processing fee, etc.).

By having additional parcels, investors can generate more equity and value compared to simply adding an ADU.