Electric drives are very doable, but a 10kw motor isn't likely to be big enough. A 35' boat is going to need a lot more HP than this in anything other than dead calm days, when going sailing seems pretty pointless. Figure you will need a 25hp minimum, and ideally 40.
Their largest engine has been used on boats up to 40 ft.
Major drawback of electrical engines is the difficulty and limitation of energy storage. This leads to a limited range, and to a somewhat lower power compared to diesels. In itself this is not any show stopper as long as one is aware of it - you state you only wnat to use the engine when mooring etc - should work fine then.
the motor is only one part of a complex system of very large cables. (talking 400 amps and more) power source, batteries alone would sink the boat, unless you could source the new type, how to recharge (generator) , a controller. and more.
I realize this is an outboard but Myth busters Jamie is spot on what your talking about.