Interrupting the yeast before they are truly done is bad.

And...

Leaving all the dormant yeast in the beer for too long is also bad.

...

Knowing exactly when to move the wort off the yeast can only be determined through gravity readings, or through experience of making the same thing many many times. But ten days / two weeks is about the time.

John: And unfortunately I'm an perpetuator of the myth at HowtoBrew.com. The 1st edition talks about the benefits of transferring the beer off the yeast.

Jamil: Well that was the popular way of doing things. But that was what, the 1st edition? Stop getting the thing off the internet. Buy yourself the 3rd addition copy and get the updated information.

John: As we've gotten more educated on how much good healthy yeast you need for optimum fermentation the advice that we used to give 20 years ago has changed. 10 years ago, 20 years ago, homebrewers were using with a single packet of dry yeast that was taped to the top of the can. There weren't as many liquid yeast cultures available.

Jamil: People didn't make starters either.

John: Right. So the whole health and vitality of yeast was different back then compared to know. Back then it made sense. You had weaker yeast that had finished fermentation that were more susceptible to autolysis and breaking down. Now that is not the case. The bar of homebrewing has risen to where we are able to make beer that has the same robustness as professional beer. We've gotten our techniques and understanding of what makes a good fermentation up to that level, so you don't need to transfer the beer off the yeast to avoid autolysis like we used to recommend.

Jamil: Unless you are going to do long term at warm temperatures, but even then we are talking over a month. I thought about this as well and I think one of the reasons autolysis....and the fact that people were using weak yeast in inappropriate amounts and the transfer would add some oxygen to it which would help attenuate a few more points. I think that was part of the deal why transferring was considered appropriate years ago.

John: But these days we don't recommend secondary transfer. Leave it in the primary, you know, a month. Today's fermentations are typically healthy enough that you are not going to get autolysis flavors or off-flavors from leaving the beer on the yeast for an extended period of time.

Jamil: And if you are using healthy yeast and the appropriate amount and the thing is... homebrew style fermentors..if you are using a carboy or plastic bucket which have that broad base when the yeast flocculate out they lay in a nice thin layer. When you're dealing with large, tall...one of the things you know people go "Well the commercial brewers they remove the yeast because it is gonna break down, die, and make the beer bad. We should be doing the same thing." That's where alot of this comes from. But the commerical brewers are working with 100 bbl fermenters that are very tall and put a lot of pressure on the yeast. The yeast are jammed into this little cone in the bottom and they are stacked very deep and there is a lot of heat buildup. The core of that yeast mass can be several degrees C higher than the rest of that yeast mass and it can actually cook the yeast and cause them to die faster and cause those problems with flavor and within a couple of days the viability of that yeast which the commercial brewers are going to reuse is going to drop 25%, 50% over a couple of days so they need to get that yeast out of there. You don't have that restriction as a homebrewer. You've got these broad fermenter bases that allow the yeast to be distributed evently. It's an advantage for cleaning up the beer. You have the advantage that the yeast don't break down as fast. You don't have as high a head pressure. There are a lot of advantages

so can i dry hop in the primary?

And then once it's in the bottles (not yet, as per discussion), is there an ideal waiting time? Still basement storage preferred?

Also, if I understand correctly, there is lots of stirring recommended while it simmers, vigorous pouring when you put it in the fermenter, then very quiet transfers to secondary fermentors and/or bottling containers, with some folks recommending gentle stirrig for the latter to get the sugar well mixed (but others opposed), and very quiet transfer to bottles. Is that right?

If you are using liquid yeast or using a yeast starter, you should be able to dry hop in a primary fermenter without any legitimate fear of off flavors caused by autolysis.
If you just dump a package of dry yeast into the wort, than you should probably transfer it to the secondary.
Under attenuation is a much bigger problem in home brewing, and home brewers are more apt to have issues arise due to under pitching yeast than they are from having beer sit on the trub or lees for too long.

On Sunday I started my first attempt at a high alcohol IIPA super dry super hop bomb.
16.5 lbs of grain 10 oz of hops and a pound of fuckin corn sugar.
I had to break out the mash tun cooler because I could never fit all that in my brew bag.
Ended up at 1.082
Pitched a 1.4L stir plate starter of Wyeast 1272 that I made the day before.
Four days of brutal fermentation and this beer still has an 8 inch krausen on it, really cool to see that much action.

I also did a 2 gallon second runnings of a really low alcohol beer. Just because everything was going smooth. Unfortunately my options for yeast were slim. I had an unmarked yeast cake I had saved from a previous batch probably 4 months old , "brewers yeast" that you buy in the grocery store (we use it for bread), and some campaign yeast. I couldn't get the cake to take off at all in a bowl so I tossed it out. I went with a tablespoon of the grocery store brewers yeast... after 2 days it hadn't started up at all. I pitched a teaspoon of champaign yeast and now it's going alright. Pretty sure this is going to be shit though.