Both seasoned and new real estate investors have a powerful tool: the 1031 tax-deferred exchange.

I didn’t even realize biggerpockets had all these tools, thank you so much!!  

I have subscribed to propstream and have a way to create a funnel but I would love to hear feedback on how to use this tool or any other tool to effectively get houses under contract and to use my time efficiently.

BP has various tools to help you analyze your deals (rentals, flips, wholesale, etc). : https://www.biggerpockets.com/investment-calculators7.

Our attorney explained the "DOS clause" as a tool lenders can, at their option, exercise in the event a transfer has occurred. 

BP has various tools to help you analyze your deals (rentals, flips, wholesale, etc). : https://www.biggerpockets.com/investment-calculators7.

Cost Segregation is a commonly used strategic tax planning tool that allows companies and individuals who have constructed, purchased, expanded or remodeled any kind of real estate to increase cash flow by accelerating depreciation deductions which can defer state and federal income taxes and increase cash flow.When a property is purchased, not only does it include a building structure, but it also includes all its interior and exterior components.

Does anyone use a tool of some sort to plan out a cash flow tree with rentals? 

In my view, it'd also be wise to have emergency reserves available for your duplex as well, separate from your personal reserves.Roth IRAs are great tools for investing, assuming you qualify to do so based on earned income thresholds.

At the end of the day it should be a collaborative approach.