Hehe, I also rushed both my marauder and juggernaut through Balmorra class quest to get him, then completed the side quests. I thought since Quinn was so eager to send me to the Balmorran arms factory, he should see what kind of hellish place it was !
About the affection raising too fast, there is little you can do. I found that Quinn was possibly the easiest companion to gain affection with, no matter if you play LS or DS. As long as you choose pro empire options, you can often get +60 or +80 just from one conversation.
So, since you already know about Naar Shaddaa, remember those republic soldiers you meet ?
If you spared them, Quinn will offer you strategic advice when you get back at Halidrell's office and find Rathari's message.
If you killed them, you will get a small flirting option instead, your choice
You'll have a similar situation on Alderaan later on, as a light side choice will unlock more conversations that you wouldn't get if you made the dark side choice.
Then, you'll have the comment Quinn will make when leaving Naar Shaddaa, you can annoy him a bit if you want.
About Tatooine, I'll tell you more once your male SW has finished the main quest there.
You can just PM me if you want and I'll tell you about the conversation choices
Anyone else remembers anything about Naar Shaddaa ?
@Bright_ephemera : I know you are quite an expert on the subject, you'll know if I forgot anything