Re: bilge pump and nav lights?
Always good to have a backup plan so I would install a bilge pump, you may never need but it will be there if you do.
As to nav lights, I am not up on my Scottish marine law so get with someone that is and see if you need them, if you ever think you will be out after dark instal them, again they will be there if you need them.
I will say few thing nicer than a sunset on the water.