Lender won't finalize a loan. Options?

[Gustavo Orozco]

I've put an offer on a home that was accepted about a month ago. After providing all paperwork the underwriters asked for I'm about 53% debt to income. This was due to the fact that they had my rental as a primary. After that got changed they asked for a lease agreement and proof of first months rent which I gladly provided. Now there looking to try to use my overtime as additional income. For what? Was the lease not good enough? So my question. Is it illegal to rent out a couple rooms of this property after I get it? And if I provide a signed lease from the future tenants and proof of first months rent, would that sway things in my favor?