Kroma wrote:

snip

My question is, is it safe for me to twist the handlebars like this
everytime I store the bike and then to realign the handlebar (all done with
an Allen key) ready for cycling? Will I eventually wear something down or
is this a common activity?

As long as no cables are getting stretched or kinked I'm sure it's fine.

There are also some folding handlebars on the market, but the ones I've
seen at trade shows still require an Allen wrench, i.e.
"http://www.humpert.com/en_media/bikeparts/downloads/montage_sicherheit/visuals/lenkerbuegel/HandlebarX-ACTFHS2_E.pdf"