The pass looks like something I will get in Carthage (maybe J) as by the time the event ends it's a lot of bonus goodies for the diamonds, though better for a new city than an established one.
As for the event building: hard pass. Yea, more attacker def is good for doing more GBG, but even in the space ages the 34% can be surpassed with 9 lv2 SOs, so, as with every other attacker def building: if that's why you're getting it, don't bother and use SOs. If the event building gives other things you want (FPs, attacker atk, maybe goods) then the attacker def boost is a nice bonus. This building is large and gives 0 FPs, 0 attacker atk, and so is of no use to me. Other players may really think the goods provided is enough of an offset to make this worthwhile, I don't...goods are nice, but if I need more, I'll run more RQs.
(yes, 9x SOs is 18 dailies, but they are also available in many events rather than just 1/year, and they don't require a road so are much easier to drop into your city)