Yes
Certainly, you can also use 2 mono amps to power left and right stereo channels. One for each channel. Using one mono amp for stereo results in a mono output though.
A mono amp will not sound good with door speakers. There are to be used with subwoofers
2
You can find that answer at Crutchfields.com under support
This depends on your amplifier's specifications. i would recommend looking in the amplifier's service manual to avoid disapointment or damage to your amplifier or speakers.
Yup
Yes, a 4-ohm amplifier can run 2-ohm speakers, but it may lead to overheating or damage to the amplifier if it is not designed to handle the lower impedance. The amp will see a lower load than it is rated for, potentially causing it to draw more current than it can safely handle. It's essential to check the amplifier's specifications to determine if it can operate safely with 2-ohm speakers. If not rated for 2 ohms, it's best to use speakers that match the amplifier's impedance rating.
That would make a total of 20 speakers. Sony sells no such system, nor do they sell an amplifier that can connect that many speakers.
a channel refers to the speakers or subs. for example a 2 channel amp can power 2 subs or speakers. a 4 channel will power 4.
The TV will need to have AUDIO OUTPUT jacks to connect to the speakers or a amplifier to power the speakers and subwoofer.
no you dont There are a couple of options. you can buy a 2 chanel with 400W rms per chanel, or a mono at 800w. make sure you match the ohms of you speakers with you amp. If your amp is 800w rms at 2ohm, it's 400w rms at 4 ohms. So if your speakers are 4 ohms, they wouldn't be getting the power they need. And remember you can blow speakers by under powering them, but not by over powering them.
If you connect three 4 ohm speakers in parallel, the amplifier would see a load of about 1.3 ohms. This definitely could damage the amp if you drive it too loud.