1. There's a lot of ratios one could make from CF data. One of the more common would be Cash From Ops divided by net income, which gives you an indicator of earnings quality. Something close to one is "solid", anything else needs some clear explanation.
2. Revenues less expenses less "maintenance" Capital Expenditures. If you don't have a good idea how to separate the "maintenance" CapEx from the rest, assume it all goes to maintenance.