No, seats are sold separately. Note you will need an elongated seat.
Not as far as I know, we didn't change anything just installed it and we love it. It is a bit loud when flushing, but that is okay with me. Great toilet.
Probably louder than what you have.... the best way to explain the sound is that it is similar to a commercial toilet without the tank that you find in businesses. It is air assist and similar to the rushing water sound you get from a commercial toilet. You do get used to it. The up side is that we have have zero toilet issues since installing it.
No, neither is included. Note that the height of this toilet may require a new water line if it is a replacement.
Hi, this is Laura with Kohler Co. I am happy to assist you with your question. We recommend replacing the complete toilet as the older bowls are not compatible with the new tanks. Thank you for choosing KOHLER.
32 psi is the quoted minimum pressure
Yes, I did with mine.
Hello, my name is Sarah with Kohler Customer Service. I'm glad to answer your question. The suggested toilet seat for this model is K-4650. Thank you for choosing The Bold Look of KOHLER.