In vanilla Skyrim, we all know how badly it svcked to spend 10 minutes to have to place an object in your house. Only for the said items to be strewn around the place once you enter again. Will Hearthfire A. Make the object placing easier. B. Stop all the items being thrown around?

It would be stupid and lame if the decoration bugs aren't fixed with Hearthfire.
However I can see this happening.

I guess it could be done if you had the in game option of setting items as fixed when your happy with their positions, some house mods have most items fixed so things don't fly around the house. Not sure if we would see that happening, of course it might also be that items you make may only have certain locations where they can be placed. Just speculating!

the physics are kind of wonky when you put your own stuff around, I made a silver bowl filled with jewels, to show off my richness to poor people visitors. But when I first put it down, they were hopping all over the place in the bowl, then I left the house and came back and they had spilled all over the table. I'm pretty sure those were just diamonds, rubies and emeralds, not soul gems with restless souls so they should not be jumping.

For those of you that don't know, to stop the game from throwing all your stuff around once you've placed it oh so perfectly in your house, you simply drop everything you want to place on the floor, leave it where it lays. Leave your home, save your game, then reload your game. Once you go back inside your house, your stuff will be still be on the floor and you'll be able to place it where you want it and it will stay there.

That's not the problem. Not for me at least. There was an update that caused how items react when you pick then up to become inverse? Maybe.

When you pick up an item, it will flip and you'll be holding it upside down. It's annoying and makes decorating my cub board with Black Briar Reserve quite difficult.

no.