Summoner...

[Delmuir]

Do you +% damage equipment affect the summons? How about things like +fire damage… do they affect Drakes, etc?

How about +crit%? Magic crit?

[Mewtarthio]

Summons inherit the following from their summoners:

• APR
• Any % damage bonuses/penalties, including those from items and status effects (such as stun, daze, and the Meditation talent)
• Any damage penetration, including those from items
• Stun, confusion, pinning, and blindness resistance
• The Magic stat, but only if the summoner knows Blighted Summoning

They do not inherit critical rate or critical multiplier. Summoners still care about those stats, however, since the summoning abilities themselves can crit (boosting the summons' talents). Note that it's mind crit, not spell crit, that matters. Spell crit is mostly useless for Summoners.