Has anyone actually made a legitimate alphabet key thingy?

[ReneZ]

I suspect most languages do better on (a) (can guess how to pronounce) than (b) (can guess how to spell).

Even when the rules are clear (as in Dutch with verb conjugations ending with -d, -t or -dt) many native speakers have trouble with spelling.

English of course is notoriously bad on (a) as well as (b).

Thai has to be the worst when it comes to (b).
These two words sound exactly the same:  ทำ  ธรรม