Congratulations on your wedding! It's been heinous on my side, or I would have said so sooner! I love your dress, and the two of you look beautiful together.
As for the newsletter, I wish everything would write itself! I've been writing papers for grad school the last few days, and I am feeling the same way you are!
Why justify getting married at Disney? It's Disney! I agree. Who wouldn't want to get married at the most magical place on Earth? But we're biased...
As for Pop Century, I wouldn't try to make it sound more expensive than it is. We always stay there, and that's where everyone in our families are staying for the wedding. My brother and his wife, who prefer more expensive places, said he would rather stay at Pop Century this time around anyway because all Disney resorts are nice. Last time he stayed at AKL and they only slept in their resort, making it crazy to spend $300 a night when they were in the parks all day anyway. Pop Century is fun. I wouldn't stress too much about making it seem fancier. They have a pool shaped like a bowling pin! Focus more on the fun stuff and people will get excited.
I love the PhotoPass idea. I wish I could get that together for our group, but I don't think any of them would go for it. They all have their own expensive cameras, so I'll just have to rely on them sending me their pictures if I want to make a favor later.
Keep your chin up on the newsletter! It'll be written before you know it!