@ Arsey - master of the understatement!
I have found that despite their bulk, certain variants of the SKROSS adaptors have been the only ones to have the most functional conversion-to-continental Europe pins, and also USB interfaces (see example:
https://www.amazon.co.uk/SKROSS-1-3...tronics&sprefix=skross,electronics,61&sr=1-22) but I do like the lower profile/weight of the MINIX that Arsey identifies. SKROSS can be too heavy and pull-away from some power sockets.
I finally found the 'lightweight-smart-casual-but-supportive-city exploration-footware' with Sketchers range (for example:
https://www.skechers.co.uk/collections/mens/arch-fit/) and there's currently a 20% discount coupon from the corporate site.
Non-M/C luggage: I have become a fan of the 'Victorinox' brand for luggage: they come with a '1+10-year' warranty and have happily and promptly replaced wheels broken by airline baggage handlers. I am forcing myself towards carry-on only (4x wheels for ultra airport mobility) and have just discovered the 'Victorinox' 'Crosslight Boarding Bag' combination of backpack/carry handle non-frame bag (37 Litre capacity) that is functional for smaller aircraft overhead lockers, where soft-sided luggage has more functionality than hard-sided cases with wheels. See:
https://www.victorinox.com/uk/en/Pr...d-Messengers/Crosslight-Boarding-Bag/p/612423.
Some airlines allow a backpack AND a carry-on sized suitcase and so this model allows for the pass-through of the backpack to fit over the extendable handle of the 4-wheel carry-on and you can board with both. Again, I recommend Victorinox:
https://www.victorinox.com/uk/en/Pr...-60-Softside-Frequent-Flyer-Carry-On/p/605406. Perhaps just keep in mind that a wheeled-carry-on is going to weigh about 4kgs before anything goes inside (although airlines currently, seem to have universally stopped checking the weight compliance of carry-on baggage).
Packing cubes and/or plastic bags (to pack street shoes, avoiding soiling, and to segregate dirty clothes). Victorinox have a 'Packmaster' that enables the flat-packing of ironed shirts that can survive travel and be ready to wear:
https://www.victorinox.com/uk/en/Products/Travel-Gear/Accessories/Medium-Pakmaster/p/604999.
Hope these bits and pieces - in whole or in part - might be of help!