Is Ryanair safe? I'm not referring to the quality of the service!!?

It is totally safe. They are so cheap because of baggage allowance, on board catering (THEY DO NOT FEED YOU DURING FLIGHT AND EVEN DO NOT GIVE YOU A FREE CUP OF WATER). Selling food and drinks during flight makes 15% profit for this kind of airlines. They need only 2 instead of 4 stewardesses on board of 737. And i as an aircraft engineer can tell you that there is no such a thing like second hand parts for air planes. So buy your cheap ticket and fly. But don't forget queue first before boarding, because they don't ign you a seat in your boarding p.