Congratulations! Who cares if you were in last place, you finished and met the SS1K criteria -- and are here to tell about it. That's what matters.
1) Yeah, your butt will feel better in a week or so.
2) My engine always starts sounding funny after 6 or 8 hours in the saddle, too. A few other worrisome things always appear to start happening ... but they seem to be my overactive imagination fueled by anxiety. Check again after your butt starts feeling better.
3) Riding at night takes experience and the realization that you need to slow down, even on familiar roads. Can't see the deer or the gravel as well. Every IBA cert ride requires nighttime riding, however.
Posting photos isn't easy. First, find a "photo hosting website". The consensus here is Photobucket. Upload your photos there, then use the link (URL address) for the photo to post it here. You do that with the little green box -- I think it's a picture and picture frame -- in the edit menu. (It says "Image" if you hover over it.) Copy the link to your photo/host site, and paste it into the space that appears when you clik the "Image" button.
NOTE that the URL/link MUST end in jpg. Make sure Photobucket (or wherever) is saving them that way!