You're going to sell half the house to an entity that will rent it out, but you will keep the other half? This certainly does not fit the spirit of section 121, and when you sold the other half (whenever that is), you certainly would not qualify for the exclusion on the other half.
Then there is the fact that the entity you are selling the house to is a related entity. I admit I don't understand the additional implications of that situation.
Basically you want to have your cake and eat it too. Sell half the house and get the exclusion, and rent half the house for an income without having to manage it yourself. My hunch is you would not qualify for the exclusion, and if you do want to claim it, you would want professional tax advice from someone you hired and who will represent you if you are audited, and not just take free advice from strangers on the internet.
