First time investing in multi-family aparment and few questions

[Mtgtme Mtgtme]

Hello: I was offered to invest in a multifamily apartment in Dallas.here are the details: 256 Units apartments in southeast Dallas submarket. Average unit size 850 Sq Ft Property is situated on high traffic roads 175.$900 K spent to renovate the exterior and amenities. Value add opportunity to upgrade the 82% of units. 

5-year business plan with 15%IRR with 8% cash on cash. Cost segregation initial study is done and 50% depreciation can be taken in year 1 with bonus depreciation and 80% in 5 years. An additional upside is not included in the underwriting (upside from the laundry room).Assumption Loan is approved for 79% LTV. The minimum investment is $50,000. A management company will be managing the property.

Here are some questions.

1.I did not understand this paragraph at all. 
5-year business plan with 15%IRR with 8% cash on cash. Cost segregation initial study is done and 50% depreciation can be taken in year 1 with bonus depreciation and 80% in 5 years. An additional upside is not included in the underwriting (upside from the laundry room). Assumption Loan is approved for 79% LTV. 
Can someone share your experience?

2. Also is it a good investment? What questions should I ask? What red flags should I look for.

Please let me know.