Or any other options you prefer such as a 1031 exchange?

It depends on the number of Units, Residential or Commercial, Apartment Complex or mix of Single Family and Multifamily.Under 25 unit - Tenant Cloud, Rentech.Under 100 - Then Doorloop/Buildium.100+ - AppFolio, Yardi, Rent Manager.Apartment Management : Yardi seems to be wildly usedSingle Family ( Mixed ) - AppFolio seems to be popularRent manager has a good customer support team.

Are you printing standard envelopes #10 etc or do you print any heavier weight or custom size envelopes?

I prefer properties that are heavily focused on the residential component  because mix-use assets receive far less attention than multi-family assets.

There are a ton of CRMs out there but we use Zoho for its ease of customization and integrations.2.)

For some people, it is a preference thing and that is fine too.

However, in the long run, I love the "buy a house a year" strategy (as a primary, for preferred financing) and just keep moving (pending that your spouse is on board with this of course, if you have one).

Prefer to cashflow as close to day #1 as possible.No problem!

I recommend you consult with a lender with expertise in investing, preferably someone local to you, to discuss the lending options best suited for your goals, strategy, and tactics.

The easier it is for someone to click on something, the less likely they are to be a serious customer.