re capping

Not really.  Replacing worn out electrolytic caps per manufacturer specification is very different than improving by finding "better" caps.  These "better" caps can, if not chosen carefully, not only make sound worse but also damage gear.

Capacitor goes with loud bang because of avalanche effect. Capacitor is charged in narrowed current spikes of very high amplitude. That creates losses and heat with ESR of capacitor. When capacitor dries out ESR increases causing bigger losses and bigger temperature increase. Since temperature also increases ESR at one point it will lead to explosion. Because of that all electrolytic capacitors have some form of fuse. I agree with gs5556 - you will hear loss of bass definition and 120Hz buzzing way ahead of that.

or the past 6 years i only use my equipment like 6 hours a week. should i worry about the 'caps'??

Not for at least 20 years.

Recappinig and upgrading caps are two different subjects.

It depends what do you mean by "much better".  Do you mean lower inductance, like slit foil caps, that are very expensive, or lower ESR caps that might cause rectifier damage?  When you recap 30 years later original capacitors don't exist anymore, but I would check their specifications and look for something similar and not the "best" available.

Electrolyte is simply drying out.  Each 10degC temperature increase shortens the life of capacitor by factor of two.  Capacitor rated  60,000 hours at 25degC wil only last 30,000 hours at 35degC, 15,000 hours at 45degC  etc.  This can be found on many datasheets.

http://www.illinoiscapacitor.com/tech-center/life-calculators.aspx

My experience has been, that when caps sit without a charge, that is when the tend to dry out.

They dry out more when amp is powered because they get hotter.  I replaced supply caps in Cambridge amp and bass definition improved greatly.

It depends on time and temperature. If they are at low ambient temp. then most likely they will last for 50 years. If playback increases temperature they will dry out sooner, but 8 hours a week is like no use at all. I would not worry. Will you last 50 years? :)

When capacitors dry out ESR increases usually reducing bass control (wooly bass) and/or increasing audible 100/120Hz ripple. Capacitor might also get hotter because of high RMS value of charging current and increased ESR.