I'm gonna fall into the neipa category here for a couple reasons, been brewing for 12 years, pushing the limits of gallons allowed per year legally and it's my favorite to brew (and drink) because of the challenge of perfecting it and the ability to play around with the numerous variations of...
Car show last weekend, weather didn't cooperate but still a good turnout. My trunk tap setup, signed by all who had some, 4th year running, gonna need a new board soon, and apparently a second keg for next year as this one kicked halfway through the weekend.
The idea of dry hopping at lower temps is to avoid hop creep and lower hop burn on heavily hopped beers. I dry hop at 55f when my dry hop load is 1.5oz per gallon or more. Assuming you are referring to a 5 gallon batch then you would be at 1 oz per gallon which is still a decent amount of dry...
Cold crash
Inline filter of some sort, I use bouncer brand.
Take your time. Slow transfer will help reduce kicking up any settled trub.
As mentioned above you'll have to come up with a process that works for your system and equipment. Everyone has their own techniques and it may take a time...
I agree that it would be in the water, I bypass my softener when filling my kettles and have a ward labs report of my well water and adjust from there. I've never had a salty taste in my beers, and I am sensitive to salt.