I'm not looking to replace my primary computer. I'm looking for a secondary device (one device, not 2 or 3) that can do a handful of things that I most often need.
The main reason I want to hook a device like that with my TV is so that I can download and watch movies (from torrents). AFAIK you cannot do that on the iPad. I'm I mistaken?
You use a real computer to download the torrent. Then you use a real computer to transcode the movie for your iDumb device. Then you use real computer with iTunes to upload the transcoded movie to your iDumb device (you can skip this step and stream the movie to the iDumb device from your real computer which surprisingly is not called iAirPlay).
Either that or you purchase the movie in iTunes on your iDumb device and watch it there.
Yes, there is... if that's the complete set of things. The iPad can do this.
ebooks/pdfs, browsing, videos, TV hookup - all there and straightforward.
text editor and git (GitHub, in this case): http://worqshop.com/
there are also other editors that have SFTP and SSH programs.
I'm not saying you should replace your current computer with an iPad. I'm saying that based on the list you've given here you could.