Acrobat XI Pro: Zoom - how to set zoomlevels and key?

Within Acrobat XI Pro I wish to change the zoom key from CTRL-plus/minus to just the 'Plus'/'Minus' on the keyboard

So it is similar to Photoshop and some other applications.

Is this possible?

Secondly, I would like to change the zoomlevels, e.g. increase to fixed levels.

e,g,

30-50-60-70-75-80-85-90-95-100-105-110-115-120-125-150-160-175-200-225-250-300  (etc.)

vainly searched for these settings, so probably it is not possible, i.e. zoomlevels are hardcoded?

Thanks

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