Recast: 25% equip, 25% PER spell. However, you can't exceed 50% recast reduction.
Melee:
From what I've read haste cap on melee swings is 70%.
You read, but the post in question didn't say the cap for melee haste was 70%. The cap for some delay tiers was around 70%. The idea is essentially, if your weapon falls within one of the 5 delay tiers, as all melee weapons do, the tier has a "lowest possible delay". So you can't really say "this % is the melee haste cap", because its going to be different for each weapon. The tiers seem to coincide with the 5 different TP return tiers.
So to be clear, the lowest delay you can have on your weapon is based on static number for the delay tier of your weapon. The % of haste needed to get to that number will be different for each weapon with different delays because its not limited by a haste cap, but by a delay cap. Two weapons that have similar delays that fall with in the same tier will be limited to the same delay limit, but the haste needed to achieve that delay limit will be different. Weapons that have a similar delay but fall into different delay tiers have 2 different delay limits because its set by the tier they fall under. The only time when the max haste would be applicable to more then one weapon, is when the weapons in question have identical delays.