Most people have answered your other statements pretty well, so I'll just grab this one:
Originally Posted by prashady
4. why do manufacturers keep making phones with physical buttons when clearly android (post gingerbread) is meant to use onscreen buttons only.
It's probably due to market research. On screen buttons may not sit well with a manufacturer's targeted market. It doesn't necessarily sit well with everyone. Also, I wouldn't say Android is designed to use on screen buttons only. Android is about choice and customization. People can put onscreen keys on their Galaxy S3s (that have capacitive buttons) with a fairly straight forward mod. IIRC, it's a setting to enable/disable them in some file. If every Android phone was meant to have on screen keys only, I doubt Google would have made it so easy to toggle.