Wow! I am going to jump right on the bandwagon, here.
Get yourself in an active fellowship! They will funnel goods your way and you can rock out with your...well, you know. You make me wish I played your world and could invite you. I am almost tempted to start a city there and join you, but I would have to quit my job if I invested any more time in Elvenar.
As for the event buildings....
1. It is always ok to go for looks. I find many of the phoenix buildings to be the most beautiful in the game. Love the Galactical Phoenix Egg (find it in someone's city if you can, the whirling blue is not apparent in the still pic).
2. Where you are chapter-wise, I second that population and culture will probably be best for you. You have some squares taken up by "regular" culture buildings (ones you can build from your culture menu). You may want to find something that will fit in the same spot without shuffling buildings around. For example, where you have the Spot of Whispering Trees, you could put a Phoenix Excursion (Day 21). It is the same size and shape, higher culture than what you have now, plus population! Or, if you move those unicorns with it, you can fit in a 4x4, like the Phoenix Nest.
You have 3 Orange Trees, which would equal up to a 3x3 space. Sculpture of Phoenix, Passageway of the Acolytes, or Unobtrusive House would fit there. You can go pure culture with either of the former and just decide what you like the looks of better, or go for some goodies with the latter.
3. With less space, you will definitely be happy with those smaller buildings. I kept my Spring Pavilions around forever because it was easy to put them alongside other buildings and fill up what would otherwise be wasted space.
4. Buildings that offer coins and supplies very rarely provide enough of either to make a difference. I would concentrate on pop and culture (and what you like the look of!), and if it also gives coins or supplies, just view that as a bonus.