Find a local knowledgable opinion.
Alex, I think you might be best served by having someone knowledgable on rigging, recomended by a local club or racing group, drop by your boat and have a look at the rigging. It sounds like it hasn't been adjusted or tuned in quite a while. This is a good place to start. Depending on the past useage and the stresses placed on the boat, the rigging could be in serviceable condition or, possibably, worn out.I'd bet the majority of 20 year old boats, lightly used, are still using original standing rigging. After the inspection and tuning you can setup a schedule for any needed replacements at a rate that fits your budget and time.If the boat has been raced or has high ocean crusing milage this inspection is even more needed.Good luck, Ray