It's a hebe and a lovely one at that. When you cut it back try to think about maintaining a nice shape and don't ever cut back below where there is growth. So basically you can cut it back but where you make the cut make sure there is still growth underneath that cut and you should be fine.
Yes, I think it's a Hebe pinguifolia. In my opinion they're one of the nicest Hebe's. They generally have a white flower around about this time of year so look out for flower buds before you start the haircut.