A line over the 9 makes it a 5. ;) (Not just by voting.)
The start is pretty fast if you actually play it. I got 62 levels after 2 hours. (Second game with all the knowledge and almost always 500% boost.)
That's not possible for me anymore. Whenever I have an object clicked I can't move the mouse out of the game. (Well you can right click and them move to the top of the game, right click again and then move and release at the same time.)
No it doesn't work offline. Upgrade costs 20k when I'm remembering correctly. The next upgrade 80k and then 180k.
The pet should be better but you should have both later.