W/O seeing the situation, there is 'expandable' cement that can be used to fill the cracks, Usually, hairline cracks are undercut so the cement can get 'in' there, and expand when it sets. I wouldn't do this until the water problem outside is resolved. Depending on the degree of severity, if you do it now, the 'fix' may not work if the pressure is substancial. (The outdoor fix may be sufficient to 'reduce' YOUR problem where as the cement will work just fine.)
In the meantime, keep on the contractor/association, and get stuff of the floor. Most homeowner policies will now only cover the major appliances down there; not personal belongings. (At least that's the trend.) Read about 2 kinds of cement - SPECCOPL and W10. There are others and I'm sure you can find them at the Home Centers. If you're at all uncomfortable doing the prep work (which can be dangerous due to flying stone/cement from chiseling), have a pro do it. Or insist the Association have a pro do it. My best to ya and hope this helps.