The lonely is from few folks visiting your dragon. If some other people visit it it'll not be as lonely but happy about the visits now and then. Though it seems to go back to being lonely also. I would guess it's based on how many other people visit your dragon per hour or something. So your dragon can be happy and content when you visit it often, but a bit lonely at times due to few others visiting it at times. Complicated but I think that is how it works. I try to visit other folks' dragons after I've visited mine.
Dragons can wear only up to 6 items. And certain dragons can only wear certain items. All dragons can wear 2 rings and a necklace. Westerns can also wear 1 each of a dragon scale arm bracelet, dragon scale leg bracelet and dragon scale tail bracelet. Which certain dragons like my Fur and Eastern can not wear. A bit complicated but I guess they wanted to make each type a bit more unique.
You can get a 2nd dragon when the first gets up to 30. and your third when your 2nd gets up to 30, ect. You can have a max of 5 dragons, but with there being 6 types means no one can get every type of dragon. I've noticed some folks get only 1 type of dragon. Someone in the Fur dragon clan has 4 fur dragons, 1 of each element.
Hope it helps and isn't to complicated.