Hi Brad, I believe a 401k loan may be helpful in terms of putting toward a down payment if needed. 

It is one reason most LLs will not accept CCs for rent payments.

We currently accept rent from tenants using a variety of 3rd party apps-Cashapp, Venmo, Zelle but are moving away from accepting payments in our individual names and want to start accepting payments directly to the LLC/business accounts, but LLC accounts do not accept Zelle and there is a fee for using business accounts on Venmo.

I do not see why a down payment in real estate is "tricky".

If the tenant misses a payment the full amount becomes due. 

Just be sure to clarify that she isn’t a leaseholder but is authorized to reside in the unit.If you’re concerned about liability or want more peace of mind, you could ask the primary applicant for additional security, such as a higher deposit, depending on what’s allowed under Colorado law. 

Can a down payment assistance program be used with the 203k?

Lock down the spot get it secured...That is exactly what we're looking for.

After talking to another family member they said they would be willing to go in on the duplex and offered to pay the $40,000 down payment and help with any repairs but they want to be "partners" or "own" a percentage of the duplex.

The payments are super easy!