Buy and leaseback contracts

Q: I want to ask about buy and leaseback in Islam. Is it allowed?

There is this company selling shops in a mall with this buy and leaseback contracts where we own the shop but rights of giving it on rent resides with company and we get a fixed rent of 0.7% with 10% raise per year.

Also the company guarantees 20% price appreciation per year if we sell the shop back to them. All these are written in a single contract. Isnt this just the same as keeping money in banks with a fixed profit?

Hurmat-e-musaaharah

Q: My father died two years ago. I was suddenly touched by my mother and I felt lust. What is the ruling for this?

I am unmarried now. When I get married:

1. Are my children allowed to marry my own brother's/sister's or step sister's children?

2. Can I marry my mother's brother's daughter?

Obeying Nabi (sallallahu alaihi wasallam)

Q: Is it mentioned in the Quran that obeying the Messenger is obeying Allah? When I asked someone that who should we obey more, Allah or the Holy Prophet (Sallallahu Alaihi Wasallam)? They said obeying The Holy Prophet (Sallallahu Alaihi Wasallam) is the same as obeying Allah. Does it mean that we should equally obey them, wound we fall into shirk as we are obeying someone equally to Allah?