For example, one property was in a distressed market where comparable properties have seen a ~8% decline in average rents over the last 18 months (the period since completing renovation project).

Does need some updating but great bones 230k cash offer 0 day inspection period

Foreclosure lists I think can be determined at some sites like propstream (I've never used it so I could be wrong).3: networking with lawyers that do probate situation and/or divorce situations and want a quick close4: Owner occupant of a property on Hud Homestore - basically trying to help first time homebuyers buy - less competition5: tax auction and tax auction sites6: Offering on properties that have been sitting on the MLS for LONG periods of time and low balling them.7: Calling owners that have recently had their property pulled from the MLS.8: Wholesalers that are selling to you with an assignment fee.9: Low balling every property you look at on the MLS and seeing what sticks.10: FSBO with strong negotiation skills.11: MLS when you see the property really quick once it comes on MLS and put in a full price offer but it was mispriced low (I got a gem a few years ago that has probably close to doubled in values since 2020 when I bought it).12: MLS offers that you really want to ownI might be missing some others but these are the general classes of people that I have noticed. 

Is there any waiting period until I can use these proceeds, not to lend again, but to spend personally? 

My idea for an alternative is to use Bill Pay and just register the CC payment by transferring from the checking account and writing a "check" from the CC account for all the bills paid in that period.  

As long as the QI for the 1031 is in place prior to that closing you'll be fine.The only downside right now is that your 45 day identification period starts with the closing of your sale. 

In addition the Tenant may require 6 months of a ramp up/build out period before paying rent.  

For example, I tried to cancel my "Registered Agent" subscription before the renewal period, because I realized I really didn't need this service.

You can either double close or leave yourself with a long enough review/close period like 90 days to assign the contract. 

If the cap rate is breaking even or above interest rates it most likely would make sense, taking into account that in five year period interest rate have a higher possibility of coming down than going up.