For question 1 because when moving beer you want to rack ABOVE the sediment layer, leaving any solids behind, your spigot will take sediment with the beer. Since sediment is down where the spigot is.
I know some folks do it. But if you're worried so much about sediment in your beer that you're already consider a filtering setup (which I think is a waste of time and money) then obviously you have issue with gunk....
If you.re bottle conditioning you beer, there will ALWAYS be some sediment in the bottom of the bottle. That's an inevitble part of bottle conditioned beers regardless of whether they're homebrew or commercial beers.
Whether you secondary or not, you're always going to have some.
This is my yeastcake for my Sri Lankin Stout that sat in primary for 5 weeks. Us-04 yeast IIRC.
Notice how tight the yeast cake is? None of that got racked over to my bottling bucket. And the beer is extremely clear.
That little bit of beer to the right is all of the 5 gallons that DIDN'T get vaccumed off the surface of the tight trub. Note how clear it is, there's little if any floaties in there.
When I put 5 gallons in my fermenter, I tend to get 5 gallons into bottles. The cake itself is like cement, it's about an inch thick and very, very dense, you can't just tilt your bucket and have it fall out. I had to use water pressure to get it to come out.
I was able to just siphon right off the top of the cake, like vacuming dirt off the carpet.
This is the last little bit of the same beer in the bottling bucket, this is the only sediment that made it though and that was done on purpose, when I rack I always make sure to rub the autosiphon across the bottom of the primary to make sure there's plenty of yeast in suspension to carb the beer, but my bottles are all crystal clear and have little sediment in them.
Half the time I forget to use moss, and you can't tell the difference in clarity.
I get the barest hint of sediment in my bottles....just enough for the yeast to have done the job of carbonating the beer.
The longer you chill your bottled beer, the further tighter your bottle sediment will be. I recommend a week. But the longer you leave it the less will come out. I have bottles in my fridge for months that when I pour them they are extremely clear, not a hint of sediment falls through, and there is no chill haze.
But even if you have sediment, who cares? You leave it behind when you pour anyway. It's called pouring to the shoulder.
And you might want to read this about
Bottle conditioned beers.