We wanted her out due to another issue but have given her a seven day notice to cure that and she did (we are in Iowa).

Link.Then, if you choose to proceed, at least you'll know what you getting into.But...it takes two to tango, and this can be a two-way game: if the bank hits you with the DOS letter, you can transfer the property back in your name to cure the problem and play that game, back and forth, if you want/can/afford.

So if they found out a unit was rented without the approvals, there would be a notice sent to cure with a $25 fine.  10 days later another notice with a $50 fine.  10 days later another notice with a $100 fine. 

This issue of possession has critical consequences to expiration of judicial redemption rights, curing a void tax sale, and avoiding short statute limitations that allow the taxpayer to regain the property without paying the investor anything at all.

Fortunately, I have a good friend that is a structural engineer and a good contact for a geotech.The last thing I want to discover is some unknown issues that are costly to cure.

If you are involved, it has to be an eviction of the entire group, assuming they do not CURE the extended guest violation.The tenant, tho, may be able to simply give her ROOMMATE a letter telling her she must move in (usually) 30 days (check your state for what the legal requirements are, could be only 10-14).

Usually it is after they move out that I find the damage.I would probably send them a "breach of lease" notice via certified mail with the damages amount required to be paid within 14 days in order to cure the breach or the lease is terminated and notice is given to vacate the property.

Resetting the clock won't cure whatever isn't working. 

Here are the magic words:“I or we (Tenant) agree that if another landlord requests reference information about Tenant, then Landlord may provide information about Tenant’s payment history, default history (whether cured or not and whether notice of default was provided or not), neighbor complaints, law enforcement investigations at the premises, pets, security deposit forfeiture, and property condition at lease end.”Feel free to customize it for your particular needs.

The seller also represents that there are no title issues or municipal violations in the form, so those would be other grounds to terminate if you found that to be untrue and the seller wouldn't cure.