Does patching influence the final solution? What are the key features to be looked into before patching ? Anythumb rules ??

To my knowledge, Patching is a method to trick the solution into behaving properly, preventing startup problems or initializing all/part of a domain with certain values of variables. If the solution would not be stable without patching, I guess, it is tough to say whether patching it a little different or not patching at all would actually influence the final result. You should try it for yourself and see. Check out the tutorials in the User-Services center.