RE: Move more extension under >> mark
@dexter-x73 well, i don't think this is reproducable in Opera exactly the same way.
What you can do is: download that addon that @Rudrick is recommending. Keep only the addons you want visible on your toolbar, and hide the rest. The simpleExtManager addon is exactly what you are looking for.
I am using it too, and it is clean, neat and clutterfree. Usable just like you want it to.
I have a few addons visible on my toolbar, i hide all the others, and when i want to access my addons i just click the SimpleExtManager, which lists all my addons nicely and easily accessable.