Hi,
Opinions are much-divided on the 18mm lens and no doubt the responses to your post will again show that here. I'm a landscape enthusiast and hiker, and like a light weight kit. Despite that, I'm also in the camp that didn't like the 18mm and opted for heavier lenses for their IQ.
I actually started out with the 14mm and 18-55 and didn't buy the 18mm because so many people posted that the zoom was as good or better. OTOH, I also kept seeing posts from people who like the 18mm. By this time I'd bought the 23/1.4 and since it was clear that it has an edge on the zoom, I decided to look again at the 18mm. I figured the only way to see if it did offer any advantage over the zoom was to set aside the conflicting opinions, buy one and test my own. And having bought one, I found that my sample was indeed not in the same league as my 14mm and 23/1.4 lenses. (I haven't used the new 23/2). Nor was it as good as my zoom (once stopped down a bit).
I was later tempted into the 16mm in one of Fuji's big rebate sales. It too delivered better IQ than my 18mm, and so I sold the 18mm. These days, despite their weight, I take the 16mm, 23/1.4 and 60mm hiking as a landscape and nature trio. I take the 18-55 for family travel and social occasions.
FWIW the f1.4 feature of the 16 & 23 had nothing to do with my decision. I almost never use f1.4. It was purely their IQ at the middle apertures I typically use for landscapes.
Cheers, Rod