For the rear mudguards get a pair of secur clips, from SJS cyclesOn my Linear there's only one thing that bugs me and that's the rear dropouts open to the rear, making it difficult to remove the rear wheel without undoing the mudguard stays.
Or having the rear mudguard set with a BIG gap at the back, which don't look right to me.
I was advised to use 'copperslip' on the folding joints to prevent rattles/creaks.
The main thing that rattles are the grenade pins & split rings on mine which I cured with some 'Heatshrink'.
It does feel strange when you first start riding one and the best advice I was given was to relax back in the seat with a light 'grip' on the steering.