That being said see what remediation is required.

Bumping rent up $25/unit will yield either $50/month or $100/month in additional incomeIf you’re worried about time, find a property mgr and that will certainly remediate that concern. 

Has anyone encountered this and can help me with some remedies.

From what I see the cap rates on nice four plex units are running 5% to 6% (assuming 40% to 50% expenses, which should include CAPEX accruals) and by nice I mean there would only be minor differed maintenance and those could probably be remedied before closing at the seller’s expense.

We would have to look to the remedies provided for in that contract as to what enforcement remedies you have afforded to you. 

Also looking for a list of brokers/agent that specialize in listing Reo's to market our service business(Mold Remediation) to.I'm wondering also if we might be better off marketing directly to the loss mitigation depts. inside the banks.

Could this be a remedy and if not why not?

If you do, DON'T TOUCH IT, in most states (not sure in CA) you can just seal it and disclose, otherwise your will need professional remediation to remove it (approx $1500 per 1,000sq ft).  

You help assist them in any way possible to remedy whatever problem they're having and perhaps give the investor a discount on the next deal.If you didn't knowingly do something negligent, the investor is reasonable, and you do whatever you can to assist them ...then I think you should be fine.

2) In rehabbing a home, I'm planning to replace as much as I can- appliances, valves in the toilet, water heaters, etc. ..just to avoid being nickeled and dimed by ongoing repairs (plus the time they take to remediate) ...