Your CPA can allocate the cost between all the residences and then you can split the sale accordingly and get your exemption, and either report the gain/loss on the rentals or do a 1031 exchange.

Build up that account over time.The “proper” amount is a function of the age and condition of the property and or units.For an older single family house, $5,000 to $10,000 should be the minimum.For older apartments, $2,000 to $4,000 a unit should be the minimum.Some may say these numbers are too high - but if you want to sleep at night - knowing you have the cash to deal with hot water heaters that burst, or HVAC units that fail or roofs that leak; trust me if feels good to have the cash allocated to deal with whatever “Murphy” sends your way.You can “seed” this account with an initial sum and then add to it monthly from your cash flow as time goes.Hope this helps.

Have constant outbound and good KPI's to see what lists/marketing campaigns are working best and how the monthly budget will be allocated. 

Quicken download all the transaction and asks you to allocate it to the correct property or a general expense. 

We have sold all of our rental properties and will allocating 50% of the holdings into stocks and other will allocated toward real estate since we are seeing bigger price adjustments.

Your point of lack of housing versus lack of affordability of housing is exactly why it'll be primarily a renter nation, and the allocation of rent to income will tighten sharply.

Yes, that is what I am suggesting- if you got a construction loan on your properties you are in the process of renovating, you could use the cash you have allocated for that purpose for this acquisition. 

I'd even say most people ought to allocate a reasonable percentage of your overall investment portfolio into real estate, but it is best to study first and get some background in the field.

Usually I would allocate over 10-12% per month for the entire job. 

If you did, just have your CPA allocate the costs to the different components that were updated.