Mfields935

I just got this as my first road bike and I am totally in love with it. Its the lightest and fastest things I have ever owner and I enjoy every second of riding it......got the gushing out of the way now I got a few questions. This bike weighs 23 pounds....in my opinion thats light but im sure many of you would beg to differ. Now can I make it lighter? and if I did would it REALLY increase the performance? Also it has shimano components that say SIS on them. Are these good components? should they be upgraded and once again if I do will the performance increase be drastic? Also any have any clue as to the value of this bike? It doesnt have a single scratch on it's red+yellow paint and the colors are as bright as they were on the showroom floor. kept inside for 24 years,all components function as they should. Thanks in advance guys