NB Scottish 80

Brewed this on Thursday night with Wyeast Scottish Ale. Target OG was 1.047 and I was right there at 1.046.
Never had any external visible signs of fermentation -- no bubbles in the airlock at all. I know that's not necessarily reliable but it's always a little worrisome when you can't see what's going on.
Last night (4 days since brew day), I opened the lid expecting to see nice layer of Krausen. Instead, I had the ring around the side and mostly clear beer. I took a reading and it was 1.008.
Just seems kind of weird that it appears to be finished (I'm gonna let it sit for another 2-3 weeks before bottling) in four days and I never had any bubbling or anything. Wonder if the seal on my bucket is too loose.
Any thoughts or comments?

Sounds to me like you might have had a leak somewhere in the lid. As far as how that looks, pretty normal to me. That ring of gunk is typical after fermentation, and no krausen is typical as well. 4 days to go from 1.046 to 1.008 isn't out of the question either, depending on your process (pitching rate, fermentation temperature, aeration, etc). What does it taste like? After putting the lid on, gently push on it and see if your airlock bubbles. If it doesn't then there's your leak, but you might still have a small/slow leak even if it does bubble when you press on it.

I get bubbles when I push on the lid. That's why I wasn't too worried about it.
Tasted the gravity sample last night when I took it. I liked it a lot.
I did not do a starter. Pitched the Wyeast about five hours after smacking it. Wort was at 60 degrees when I pitched. I had aerated only with a stirring spoon prior to pitching for about two minutes.
I think the beer is going to be good. Just the first time in seven batches I had zero airlock activity.

I'd say if it tastes good, then you're in good shape. If there is some kind of leak though, you might want to bottle/keg it up sooner rather than later to avoid potential oxidation or contamination while it's sitting in a leaky bucket.