There's something that might need to be cleared up here.
SRD wrote:Maximum Dex Bonus
This number is the maximum Dexterity bonus to AC that this type of armor allows. Heavier armors limit mobility, reducing the wearer's ability to dodge blows. This restriction doesn't affect any other Dexterity-related abilities.
Even if a character's Dexterity bonus to AC drops to 0 because of armor, this situation does not count as losing a Dexterity bonus to AC.
Your character's encumbrance (the amount of gear he or she carries) may also restrict the maximum Dexterity bonus that can be applied to his or her Armor Class.
It is to my understanding that the maximum dexterity bonus only applies to your armor class. This means that, while your armor or load can greatly hinder your AC, all other aspects of dexterity are unaffected. Of course, my knowledge is from 3.5 D&D, not from FK, so I could be quite wrong.
For example's sake, let's say you have a character with a dexterity score of 20 (modifier of +5) that wears full plate armor (+8 to AC, max dex of +1, -6 armor check penalty). Your AC would be 19 (10 + 8 armor bonus + 1 dex bonus), lower than it would be if you could apply your full dexterity bonus. However, for other uses of dexterity, such as sneaking about, threading a needle, juggling, archery, etc., these would all still get the full +5 bonus from your high dexterity score.
Giving some kind of echo to indicate that your armor class has taken a hit could be handy, but it really shouldn't be affecting what it says on your score sheet.