I think you ought to know I'm feeling very depressed.
Can I build, for example, two Temples? If so, do I get the stacked benefits (+8 hand limit) plus 6 influence (3 for each Marble site) or do I just get 6 influence and only increase my hand limit by 4?
It may have been mentioned in the rules, but I may have missed it. Still couldn't find it.
No, you cannot build two of the same building.