Did some changes on the footbike: Replaced stem, handlebar (and shortened the handlebar), grips and bell. Regarding to handlebar and stem it didn't bring the expected change (in particular: lower grip position). On the other hand: That alone saved roughly 450g of weight.
Cleaned and lubed the head set.
Swapped the brake pads from standard Shimano to Kool Stop black and salmon. Definitely better.
Swapped tyres and inner tubes. The new Continental Contact Urban with TPU inner tubes are way more supple
and faster than the old Schwalbe Marathon Supreme with butyl inner tubes. It's lighter, too - saved another 250g.
To prevent further eye sore I replaced the neon yellow bottle cage with a reserved black one.
Current state:
E.