Kinked and misshapen doesn't mean much. Gashes, slashes, holes, tears, and that kind of thing, are significant, though. There's no harm in trying them out if you can't find any real problems. Mount them on a rim, complete with rim strip and inner tube, and inflate. If you can mount the tire and inflate to full pressure and nothing alarming happens, it's probably fine. Look it over carefully before you go for a long ride.

Bottom line, of course, is: don't ride it if if you don't feel safe on it. But if you can't find any problems, don't worry about it.