But it seems that property taxes will increase extraordinarily high next year and coupling that with expensive home owners insurance.

Cousin A, who continues to reside in one half and rent out the other, will report rental income and expenses for their portion on their tax return.

Considering the investment size and projected returns, how should I structure my financial involvement to balance the potential risks and rewards?

This is a good model but doesn't account for a return of the $500k your parents will contribute..For example if the property generates $10k per month with $6k in PITI & operating expenses the proposed return for your parents would be: $2k and $1k for each of the minority partners.

I live in the Daytona Beach area & finding something turnkey for sale that will cash flow is very difficult, the prices are still too high.

Make sure to find those receipts and invoices so that you can include those in your tax return. 

Ultimately I do not want to be over leveraged, stuck paying a high mortgage for extended time, or live in a home that needs work I can’t fund what are your thoughts and recommendations for how I should structure my first purchase?

Here’s how you can evaluate the investment potential in this area and ensure it aligns with your goals:Local Market Research: Since these are new homes and there isn’t much inventory for 3-bedroom, 2-bathroom properties, you could benefit from a high demand and low supply situation.

Try to assist them with some independence in this world of insanely high rents.   

Do you guys also attach receipts of repairs and items to replace when you return the deposit to move-out tenants?