[You want to leave that beer in primary on the whole yeast cake until it is completly attenuated. This means when you have hit a stable gravity for at least 3 days. So no secondary, generally once you transfer to secondary you have removed so much yeast that it has a hard time finishing up any remaining sugar. If you make sure the gravity is stable you can add your priming sugar and be confident that it will not over carb. In terms of adding yeast at bottling it is not absoutley necesary but it is 'cheap insurance'. You might well have plenty of remaining yeast but is is very stressed by the high alcahol environment and half packet of dry yeast is pretty cheap so why chance it? ]
So you go straight from primary to bottles once the final gravity is stable for 3 days? I assume this means less than 2 weeks? Aren't you worried it could blow bottles?
It doesn't necesary mean less than two weeks. I have had big beers take 3 or more weeks to finish. The thing to remember is that there is no set schedule here. The beer will tell you when it's done. The reason I recomend against secondary is that you are introducing an oportunity for oxidation and infection and it doesn't really buy you any benefit. If you were adding a new fermentable, say fruit, then that is a different story.
If you are worried that there is still some room for further attenuation you can wait longer than 3 days. That is just a basic rule of thumb.
To take your example of a belgian quad;
if you started with an OG of say 1.100 with a low mash temp and added simple sugars let's say you expect an FG of 1.010 or so. When you get three or four stable readings a few days apart, unless it is way above your expected FG there is not much chance of bottle bombs. There was only so much fermentable sugars in the wort originally and when the yeast stop, unless something else happens to them, it is because they have used up all they can. The priming sugar you add is more or less the only remaining fermentable sugars