Well, first off all let me tell you, vim was meant for programmers and is basically a command line editor (that doesn't mean it doesn't have a GUI). And at the start it's relatively harder to learn than other graphical editor. Other than the requirement listed, there are a whole lot of features in vim. One of them is you can undo file even if you have exit. So let's start:
Save changes immediately, even without filename
Yes, with appropriate settings it can do.
Put down this in your
Make the directory if it doesn't exists.
More info about autosave here.
Easy graphical copy paste
Vim has its own way of copy pasting, but you can start it in easy mode. Start vim in easy mode. (You can do evim instead of gvim in terminal.)
More info about evim here.
Yes, like any other text editor, it works offline.
If you are doing undo or redo in vim style, you can use u to undo and Ctrl-r to redo. For search you simple have to press and /.
If you start with easy mode (evim), you can do the ctrl-z way.
Fast to Start
Yes, mine one starts within a second. PS. I have many plugins and other vim files installed.
Fast to create new files
:tabedit filename.txt to open a new tab with a filename.
Yes, Vim has active development tree.
Works on Ubuntu
Yes, Install it via
sudo apt-get install vim-gnome if you are using GNOME as your graphical end.
Free and OpenSource