You are an investment banker structuring a $500 million Commercial Mortgage-Backed Security (CMBS) deal. Explain the process of pooling a diverse set of loans (retail, office, industrial) and structuring the tranche hierarchy (AAA, AA, BB, Equity). Detail the methodologies used to determine credit enhancement levels for the senior tranches. Discuss the potential impacts of rising interest rates on the prepayment speeds and the weighted average life (WAL) of the offered bonds.