PROFESSIONAL MAINTENANCE OF VCRS AND VIDEOCASSETTES?

Does anybody out there know what causes any and all analog VCRs, VHS and Betamax, top loaders and front loaders to eat and mangle the tapes they're built to play and record onto and what are the best troubleshooting guides for fixing them and keeping these machines in tip top condition at all times and what are the best ways, if any for repairing ALL damaged analog videocassettes in that bad a shape. Of course I realize that audio and videotapes are now obsolete in this age of DVD and Blu Ray Discs, however I also enjoy ALL sources and formats of entertainment recreation and I also would like to know if cleaning the heads of any and/or all domestic analog VCRs can be done by applying Finger Nail Polish Remover with a cotton swab as this works tremendously well when I use this method for cleaning the heads of my analog Reel to Reel Tape Recorder. I would feel very honored if anyone in the know would PLEASE answer all these questions ASAP. Thank You.