Er,
Keypad -- true.
ECS -- never heard that before.
Memory -- the game usually stated that or had 2 versions.
WB 1.2 -- never heard that before.
WHDLoad -- true.
You want compact size? You want to run from ADF's? Then run UAE on a netbook.
I've heard of that before...games not working on KS1.3 but working on KS1.2 fine. Not sure what games they are though, and I doubt they'd be that good because they'd be so old.
ECS had fatter Agnus which meant 1MB chip memory (A500Plus for example), and some old games don't like more than 512k chip memory (or any fast memory for that matter).
