I have not run into a scenario where someone ever had to remit the deposits. Typically a deposit is forfeited to cover missed payments if they were to break a lease early. A bankruptcy is set up to discharge or reorganize debts, so I could see that through bankruptcy you wouldn't have ground to pursue a deficiency for a broken lease or missed payments. Typically, though it isn't worth pursuing anyways. I have paid non-paying tenants to leave before, which is completely opposite of pursuing them for missed payments. I now only do lease options. I feel like I get a higher quality of tenant, people that treat it a little more like their own home. Sometimes they stay, and sometimes they don't, but either way they typically take care of it along the way.
As far as bankruptcy or short sale on their credit, that is going to be quite typical of most people that are looking to rent. Anyone that has great credit will not be renting, or will be for only a short time. The last few years hit a ton of people causing wildly high amounts of bankruptcy, but it doesn't mean these are necessarily bad people or poor at paying their bills. Many were mislead and just got in above their heads.
One thing I do with all my tenants, which are all potential tenant-buyers is put in a clause that they must sustain a credit repair program throughout the lease. People that truly got dealt a bad hand of cards, and are trying to "right the ship" will be perfectly fine with this.
I know there are mixed reviews on credit repair, but I did it personally for clients as a mortgage broker before the amount of people got too overwhelming. Now, I refer them to a credit repair company. We have almost always had positive results. It won't clear up foreclosures and bankruptcies usually because those are public record, but lates and paid collections are almost a given.
Sorry to digress, hope this helps.