If the lease is ending be sure you have given the proper notice of non-renewal of the lease.

I read some old posts where folks have suggested using non locking door knobs is that something tenants like ?

Even if you create a non-CA LLC, if you are managing the business from California, you will likely be deemed to be "doing business" in California and therefore likely subject to CA taxes.

Rent out part of the space at least to help pay for mortgage and utilities.  

It depends on the lender but at a min they must follow TX SML or lending laws in the state in order to compliantly lend in TX, on whether choose to apply this guideline to all types of occupancies or transaction types (non owner investment, second homes/primary residences, etc)80-85LTV on rental properties is only on the purchase for fannie/freddie loans but on rate term refinances its max 80% and cash out max 75% for 1 unit and up to 70% for 2-4 unit cash out conventional.On HELOC's and rentals are up to 70-75% depending on the HELOC investor or product.Its good to distinguish between what the lenders are willing to do and for which product and also these loan products must abide my state law as well as an additiona layer of "overlays," on top as well (whichever is worst / most conservative).

Of course, it would need to be non-owner occupied (investment property).   

If they don't, give them a 7-day non-curable.

I would recommend to all that they build a STRONG relationship with a Realtor/Broker or several Realtors, because  2.Downloaded a list of multi family owners from Listsource.com - You can get this from a Broker who can run a list of non-owner occupied properties, this features the number of beds and baths and from which you can build a mailer and network. 3.

Most prefer havng the entire space to themselves and they don't want to pay a lot.

There is a contract that is signed.These are "quick" transactions, within days, that the borrower (Subto student) needs "immediately" to provide a non refundable emd, for a Subto transaction.