All characters are unlocked. Any high scores that were attained were entered under "CAP" for those who don't like seeing other peoples' initials on a gamesave.
Well either take the image URL, ending in .jpg or .png or an image file format, and use the "insert image" button and paste the image link there, or just copy and paste the picture into the status field and it will upload as an attachment and show up in your post.