Mortgage wrap deal

[Daniel Bernstein]

A real estate agent pitched a mirror wrap deal deal to me. How it would work is that I would buy a new construction home from Lennar, and I would seller finance the property with Lennar currently they are offering around 5% interest rate 30 year fixed. Then after I buy the home I would sell the property to somebody else through seller financing. The real estate agent then said he could likely sell ~250k property for ~50k markup, and I would seller finance the property to somebody else at 7-8% interest rate. This would theoretically give me like $500-$600 of cash flow but I would lose out on any appreciation.

Concerns I have about this strategy is 
1. Lennar homes has really bad reviews: bbb, trustpilot, consumeraffairs. It has a 44.15B market cap so it is one of the biggest home builders in the US. I don't get how it can be so big but get such bad reviews.

2. If the buyer forecloses
a. if the house is bad quality and dealing with Lennar warranties is now my problem
b. now I have to be the one to make the mortgage payments to Lennar

3. Due on sale clause

I would like to hear people's opinions on this strategy if the risk/reward is worth it or to steer away