It depends if you want to keep the car for ages, or not.. as it stands you seem to be OK.
But the tranmission fluid does degrade, and people have found changing it has made a difference, so probably worth doing it on the basis that 'lifetime' is just a term, and the fact it degrading might shorten the lifetime is not factored in.
The same for shocks, whilst externally they may be fine, if they are the original shocks, they would definitely have degraded in performance.
As for the roof, that's tricky, I personally use a bit if lithium spray grease (wiping of any excess to ensure no dirt gets stuck in it), it works wonders on seat rails/mechanisms too. My Mrs Beetle Cab really benefitted from that, and whilst my e46 cab didn't need it, I've done it anyway. the only other thing which is routine maintenance is to keep the rubber seals all clean and Gummi Pfledge them.