The landlord might be in a jam.
If it were me, I would provide the information for the credit check, but I would not pay for it.
He is likely looking for a reason to deny you, however the lease is already done.
If you end up being denied access to the property then you might have a reasonable suit to bring IF you can show that you have actual damages. If you end up having to live in a hotel while looking for another place, or if you end up having to pay any other kinds of fees for staying where you currently are beyond a certain date, then those costs might be put onto that landlord.
If you aren't in a jam where you absolutely MUST move... you might want to just start looking for another place. This one already has disaster written all over it.