Yes, I had that exact feeling - I was so disappointed when I accidentally got the Celene rules alone ending and so anxious that I messed up the halla statues and all that; it really put the right amount of stress to feel that accomplishment through and through on so many levels (not to mention a random Helm of the Inquisitor drop that I lost because of the replays). *snip*
I hear ya. Personally, I only cared about helping the elves. When Lavellan met Briala, I only cared about supporting her so she could make a better future for elves. When the advisers said that it would be best to put Gaspard on the throne for her to control since she and Celene had too much bad blood, and one of the elven servants revealed that Celene had purged an alienage while sleeping with Briala (a b*tch move by any standards), I resolved to do that. I tested the "spare Celene" route just to see what would happen, but at best she banishes Briala. When my Lavellan lamented not being able to help her fellow elves afterwards and Solas kind of went, "Our people? Who are our--oh, you mean elves! Sorry, I don't consider myself to have much in common with other elves... I hope in the future you can see more than just pointed ears," I thought, "H*LL NO!" and stayed the course. I felt guilty about letting Celene die when I came to the palace to protect her, but I care more about helping disenfranchised minorities than privileged nobles who already have everything gaining more.
(Plus, Celene and Gaspard have caused so much grief with their civil war that it was a little pleasing to see that neither of them won. Celene paid for butchering elves to maintain her own power, and Gaspard got exactly what he wanted - he got the throne. He just didn't count on not being the one to call the shots.
)
Haha, I thought the same thing that Solas was enjoying himself way too much; I was a little taken aback at first, then annoyed that he could at least soothe me or something after all this hassle I was going through, but in the end he totally made up for it. 
Yeah, I gotta admit my Lavellan was a little put off by how much he was enjoying himself. She was miserable playing politics, and went over to her beloved, who is normally so nice, polite, friendly, and detached, hoping that this calming presence would help calm her nerves. (Not to mention hoped that he could commiserate as a fellow scruffy elven apostate who can't believe these sparkling liars and crooks.) Then he loved it arguably more than the nobles present, and she's like, "... Who are you??!! D:"
But once it was over and she managed to help the elves like she wanted, it was like the whole world breathed a sigh of relief and all was forgiven. The dance more than made up for it. 
I equipped my Lavellan with the grace of a queen in social conduct just to shove it in their face (and I totally beat them at their own Game), but inside I think she felt something like what a leaf must feel when a tornado drops by for a cup of tea. We were both very, very frazzled by the end there. Next playthrough (a duplicate Lavellan, sigh - I tried resisting, I really did try!) I'm going to savor each of these moments over days and weeks. First time I kept rushing ahead because I was getting more and more anxious/apprehensive to find out what's the deal with Solas and why isn't he more open with my Lavellan, and then I found out. Something died in me when I realized he's not turning up in Lavellan's chambers/dreams at the very end so my only solace is to replay the entire game and go very, very, very slowly this time. Within reason, of course.
Nice. I imagine my Lavellan messed up the first time, asking questions a little too straightforwardly in one conversation and losing some court approval, but quickly caught on to how detached people are supposed to behave and managed to "fake it till she made it." After dancing with Flourentine, she managed to become the Belle of the Ball (actual achievement!), so it was really satisfying.
(I do imagine though that at one point she walked by Solas calm as you please - then vomited into a potted plant, ignored his alarmed "Are you all right, vhenan?!", rinsed her mouth off with a glass of minted water provided by an elven servant, exhaled deeply, visibly smoothed herself over as she suppressed her nerves into a pocket deep inside her stomach, then walked back out into the ball as calm as you please and managed not to betray any more nerves until it was over.)
It is nice to savor though, huh? I was in a hurry to finish this playthrough too, so actually appreciate it now that it's over. >_<