So after talking to some developers and guildies who have been testing since beta i figured id compile a list of caps i know about. 

+melee Crit is caped at 40%
This includes 20% from dex, 5% for main handing a dual wielder, and 2.5% for off handing one, and all gear/stances that add crit

So a harmonious monk in crit stance is at the crit cap. 
Stance : 30%
Dual wielders 7.5%
more then 200 dex 5%+

+melee dmg caps at 40% from gear/stances
This includes stances and gear with + melee dmg rating.  this doesnt count bard songs or other buffs
Dragon monks come the closest to the cap with full raid gear and stance.
24% + 10% from gear

+dmg is  linked to +melee dmg cap
Ideally, youd want 40% dmg and 40% melee dmg rating for the spell bonus on secrets, but realisticly if you had to pick, naturally go for +dmg

Haste is CURRENTLY caped at 40% (This might or might not change)
20% from item, 20% from stance/spell/song

In the simplest of situations: (This is really simplified)
100% haste cuts a weapon delay in half  (2.15 fist wraps become 1.075)
50% haste reduces delay to 75% of the original
40% haste reduces delay to 80% of the original   (2.15 fist wrap becomes 1.72)

There was a minimum delay for weapons, i dont remember it but i want to say its 1.6 or 1.7 seconds. (This is definitely something that might have changed since beta)

yea id bet that that 2% was from cleave and other forced crits from bards/rogues.  cause my guildie is a harm and im drunken and we both sit at the same crit % so we both use middle stance... 2 min timer on peh with raid buffs blows him out though ;-p

1) Palm explodes the heart (lvl 50 finisher)
2) If your harmonious you can probably dump all dex and put it into int
a) 900 int will cap your secret dmg (minus songs/buffs)

most apw gear has + dmg or + melee dmg as well as + crit.

Just curious, but why a 2h sword?   The only swords are martial swords and thats more of a defensive weapon.

THey did add a bunch of new 2 handers to the game for the DK revamp, and they added a 2hb (martial staff is my guess, but could be great staff) to apw for sure.  Just have to wait for someone to find it.