Battery is not replaceable. Therefore no replacement. The appliance would have to be completely dismantled. Hepa filter can be used from the normal V12. However, it still looks like new after more than a year. I haven't even washed it yet. The V12pro is highly recommended. Hard to get though.
Yes, the G11 has the technique for cutting the hair wound on the roller that was already used in the Shunzao Z11 Pro. The brush has three sections with small blades that can cut the hair. The brush looks a little different on the G11 than on the Z11 Pro, but the principle is the same.
There are 9 parts included (wall bracket, carbon tube, floor nozzle, smaller roller nozzle, two different brushes, joint piece, flex hose, illuminated interspace nozzle. If you google the part, I'm sure you'll find a photo with all the accessories, it really does come with everything. The charger can be plugged directly into the vacuum or into the charging station. I've had it for a month and I'm very satisfied.