Got mine a few weeks back and can address this from my experience.
• Yes, you can ride normally but not the neutral gear scenario. The motor only adds a 2 pounds or so and is barely noticeable, but it has a switch under the board and on the hand control. You could turn everything on and only use when you wanted though since the charge is lengthy.
• It has regenerative breaking, so only recharges on break. But any real hill and this option is kind of a godsend.
• The motor shuts off if it goes beyond a certain degree up hill. Not ideal for this. But great for moderate or small hills to keep speed up.
I got mine E-Go Cruiser about a month ago and it really has brought back the love of skateboarding in me. Now I take lunch breaks to just hit the streets, which has a nice zen-like quality.
It is light, fast, can bowl over anything, and the charge lasts a spooky long time. The one note is the brake takes some getting used to in how touchy it can be, but by far worth the money.