Well, on the bolts, not the blades obvs.

Yay or nay?

Yes....use it. Obviously I could be wrong though.

Yes, or a little penetrating oil if you don’t have anti seize.

Yes

Kinda depends on how long between blade swaps. I've never seen the need for it, but if I were to go two years or so between swaps, I might want to go back in time and have applied it. Barring availability of an appropriately-equipped DeLorean, I'll stick with a pipe on the handle of my breaker bar. Perhaps as important is a way to control the blade while applying torque, sticking your shoe between the blade and the frame is not sufficient.

I do it on my JD Z920M. Never had any kind of a problem.

Yes, particularly if you're changing/sharpening blades a few time a season. Anti-seize, some oil or grease, anything for some lubrication to avoid galling some threads.

Always!

My vote is to match whatever the torque spec requires for safely tightening. And normally that is nothing of any kind. But it may include some oil you need to check. I'd rather not have them come off. I would never use antisieve.

I haven't tried it on lawnmowers, but I coat threads with 222MS Loctite, and that seems to do a good job of preventing screws from corroding together.

yep

YES... due to the nature of Never Seize you don't have to add it every time. Every 3 or 4 seems to do. It's good insurance.

I knew the owner of a small engine shop and they always used it. Really no chance of the blade coming off due to the normal rotation tending to tighten the bolt. Once I left a blade finger tight and started mowing... checked it as soon as I remembered and the bolt had tightened its self.

I sharpen the blades on my zero turn once a month during the season and outside of a drop of oil on the threads, I don't use anything. But I do use a breaker bar to remove them.

Yes, and you don't need very much.....a tiny bit goes a long way.

I use it on mine

You don't need anti-seize when you use a cordless impact to remove them.

I use a touch of something.

A little grease and cordless impact. Brrt off - brrt on.

If one torques the bolts, anti-seize changes the bolt rotation and torque. For a given dry torque value, one can overtighten, and overstress/stretch the bolt to cause failure. Use wet torque values.

If one removes the blades with any frequency, then anti-seize should be unnecessary.

Galling should not be an issue unless both surfaces, bolt and threaded hole, are stainless.

US made mower engines should ensure tight bolts by virtue of direction of rotation. Use caution with australian mowers, as they spin the opposite direction and the blades may fall off. Also they have no grass. Just roots.

Because they're on the bottom side, you see.

If it has threads I apply either anti-seize (of the appropriate type) or thread lock (again, of the appropriate type).

The advice about wet torque is very appropriate and easily missed by the inexperienced.