Thanks for the suggestions.
1. A lot of users use SPACE bar to scroll pages. Personally I like mouse scroll wheel better, but since shortcut keys are hardcoded right now, I cannot use the SPACE for other things. In next phase GreatNews will provide customizable shortcut keys so everybody will be happy:). F7/F8 is the default shortcuts to move to next unread channel/group.
2. You can config number of items on one page through Tools->Options->Reading tab. The default is 10, but you can increase to as high as 999.
3. Tabs are not implemented because I'm sure dedicated browsers provide much nicer tabs. But this request is so overwhelming I have to add it. The next build will include a simple tab support. The build after that will provide option to disable tabs. Sort of 2 steps ahead and 1 step back