.- Wholesaling and flipping (which is what you mean by "building", I assume) in the same LLC- Pay all business out of business, pay all personal out of personal.

We’ve faced similar challenges with larger homes, as most traveling healthcare professionals tend to travel alone or with one other person.

-if you can't go there in person, look at some properties in person, talk to some people in person, build a network in person and get a feel for an area in person, i would not buy. 

Quote from @Trent Reeve: personally, i would go with the carpet for now. its new and already in.

If a person doesn't fit into one of the two categories below, what would the point of posting on this website be?

We will be investing through a US corporation and all partners (and there are many) are foreign nationals so we cannot give any personal guarantee or collateral.

Changes some of my answer below, but here would be most of the types of transactions you would have in these accounts and between them.Property transactions would be: all property specific rents and expenses, allocated expense transfer to the master LLC and transfers to master LLC bank account for profit AND/OR property management fee.Master LLC transactions would be: Shared expenses going out, reimbursements/transfers from properties for their allocated share of those expenses coming in, the transfers from your properties deemed as profit AND/OR property management fee and then transfers to your personal accounts deemed as owner distributions.Other transfers that could occur is if the master LLC needs to transfer to the properties for capital expenditures above and beyond the reserves you might leave in their accounts.

I use my personal email (first initial last name @ gmail) for almost everything business related.

You may want to get a GoogleVoice number to separate from your personal number.

And it's convenient for life if you use your personal bank account, you can still have one app for rentals and paying friends.-  Con's:  Nothing about the software per say, but about the landlord experience.