Do I need to shorten chain going 32 to 30 front ring?.

In theory you should, in practice probably not worth the bother.

Clutch mech? try it and see, should be fine.

If the chain is still taut when on the small sprocket then you’re fine.

Depends, if your chain at the long or short end of what works on 32. I went 32->30 and left chain as it was, it was fine on both 32 or 30. When I fitted a new chain I went for a full link less, it was also fine. Might be a little short if I go back to 32 though.

I don’t bother when I swap for 24hr events

The chain is going from wrapping around 16 teeth to 15 teeth – if it’s slightly on the long side before then you can take out a full link (two teeth’s worth). If it was already perfect then you can’t take out a full link without ending up too short.

As above. On my bike, I can drop two and be okay, on the wife’s bike, I’d need to shorten it (but she could go up two no bother).

Have a look at the chain length equation on the park website.

Cheers guys I’ll leave as is and try it