I can answer the Flash game thing for you, since I have over 250 Flash games on my N900
I used Firefox to save them and run them with my N900 and no need to be on line
1. Well over (most) 50% of the Flash games are not going to work well without a keyboard or mouse pointer emulation (N900 has this via the stylus).
2. A lot of games require the arrow and space keys to work
3. Some require left mouse clicks and of course mouse movement
4. Some can "see" touch interface as mouse movement, but is VERY imprecise that way and touching the screen works as the mouse click.
In summary, I do not expect to play many Flash games well unless they were designed for touch-only interface. Based on my 253 games sample, this is less than 30% of the games I have. I have all styles:
1. Card games
2. Pool games
3. Physics type games
4. Tower defense
5. Balloon poppers
6. Tank games like Scorched Earth (I love these games and Android has REAL good one)
7. Tetris games
8. Bubble pop games
9. Well, point is I have a bunch and not too many of them work properly with just touch. Perhaps the selection will grow, now that Flash is getting released for a TON of touch-only devices? Had iPhone used Flash, there would probably be more that worked with touch-only than not
Apple is truly Evil.
Added:
Please note that some games may lock your device up and require a battery removal to restart. That being said, Flash on the N900 is full version, but older 9.4 version- Dinc is using a lite version of 10.1 (no GPU support, but still should be more stable with newer content).