Are these arranged on the same parcel?

Doing double closing to another cash buyer is an option with the use of transactional funding when the profit margin is high; is an option.You can also partner with another wholesaler and work with a profit-sharing arrangement to move the property quickly.

You will have to arrange for the downpayment amount somehow because if you don't have the funds for a downpayment, your DTI ratio might also be low which decreases your chances of a mortgage. 

As such, it is not at all uncommon to find the arrangement you have described.

In our property binder we provide the tenant with contact information for the local fire-department where they can arrange to attend a free course on the use of fire-extinguishers if they are not already comfortable with using one.

In addition to the brokering we have a strong capital markets team in house and arrange for any type of financing with equity partners, funds and/or banks and can be creative when it comes to structuring the capital stack.

This arrangement could remain with the sale.

Although, if they're paying via check, then I would try to get them on a recurring direct deposit/bill pay arrangement since paying by check is really just an inconvenience for both you and the tenant.

Your personal cell or do you maintain a different line which is made to resemble an end buyer?

A "sub 2" financing arrangement, where you take over the payments on a property, may or may not trigger the lien holder's ability to collect on the lien depending on the terms of the lien and state laws.