This is a collection of stuff I've posted elsewhere.
On the increased mana cost of 2t5 and AP...
The increased mana cost on the AB debuff is fixed. Each debuff increases the mana cost by 146 mana and reduces the cast time by .33 seconds. AP and 2t5 increase the base cost but do not affect the mana added by the debuff.
The base cost of AB is 195 mana, so 2t5 and AP add 20% (39 mana) and 35% (68.25 mana) respectively and 62% (120.9 mana) combined. When fully stacked, AB costs 633 base: 672 with 2t5 (106%), 701.25 with AP (110%), and 753.9 with both (119%).
The result is a significantly increased DPM for AB.
On gems...
The tricky gem slots to fill are always the blues to activate your CSD or hit a +dam bonus. Heroic gems can be extremely nice for this if you're gemming for regen, specifically
[Seer's Chrysoprase] (crypts) and
[Fluorescent Tanzanite] (BF).
Kreeg's
Manly currently has a list of food buffs that stack with other buffs. Most are seasonal. The exception is
[Kreeg's Stout Beatdown], which is buyable from Kreeg, in the initial courtyard, after doing a tribute run. In case you've forgotten how to do a tribute run, you'll need a rogue (or seaforium) and the mats for a
[Gordok Ogre Suit]. You don't absolutely need them, but it's easier to just do a full tribute when you're 2-manning stuff.
Value of int/spi
Socketing a 10 int gem at 750 int and 320 spi--fairly low stats, if you're stacking int/spi, you'll be in the 870/450 range with raid bufs--gives (assuming BoK):
* 12.65 intellect (non-gnome)
* 189.75 mana
* 3.43 OOCmp5 or 2.06 mp5
* 113.85 mana from evo (151.8 2t6)
* .16% crit
* 3.16 +damage (4.05 +dam spellfire)
Assuming a 6 minute (300 second) fight, the total contribution to your mana is 189.75+113.85+2.06*(300/5) = 436.2 mana, or about 2/3 of a fully stacked AB, which is a significant amount from a single gem, not to mention the +dam/crit roughly equivalent to a
[Potent Flame Spessarite].
Stacking int, in turn, makes spirit a better stat. Socketing a 10 spirit gem yields (these are I5SR):
* 450 int: 6.53 mp5
* 550 int: 7.22 mp5
* 650 int: 7.85 mp5
* 750 int: 8.43 mp5
* 850 int: 8.97 mp5
So the two sort of grow together.