1- to be fully automatic from the switch on of the pc till the games options appear;
2- to be the most bug free;
3- to show some screenshoots of the game (or video):
4- to have only the options up, down and go (start);
5- to be able to be configured for the start of games (game by game or default);
6- to be able to play mostly the old classics (80's and 90's);
OK, your spec is not altogether clear, but here goes:
1- This is up to you to setup your OS to lanch the FE from startup
2- You'll have to decide this for yourself - remember they are free

3- All FE's can do this (screenshots anyway)
4- All FE's featured in the <Software section can do this
5- Not sure what you mean, but generally the Windozy (non-cab) FE's allow you to setup INI's for each game
6- This ability is dependant on the emulator you are using, not the FE.
As for your OS - if you have an old slow PC then use DOS, otherwise use Windows XP.
Then try all the FE's in the software section to see which you like best
