Mostly bunk, or it's a least one assholes opinion vs's another's.
Finding a coffee you really like is the most important thing you can do to increase your enjoyment. Having a consistent grind is probably the most important thing you can do to up your coffee game. i know a roaster who has a two thousand dollar grinder in his house and what is essentially a nice Mr. Coffee machine to brew with. Grinding your coffee right before you brew it does make a difference.
Drinking your coffee before it gets too old makes a difference. Before the shop I tried to keep it to two weeks, now it's mostly in the week it was roasted. Some coffee doesn't taste as good right after it's roasted, it needs a day or two to gas, other stuff is significantly less delicious two days after it's been roasted. All coffee is different from country to country and even farm to farm. The way it's picked and processed, how long it's sat around, the soil, weather and probably how stinky the container it was shipped in probably all change how it reacts and tastes. People who say you have to drink it right after it's roasted or you have to wait two days are probably full of shit if you apply that advice to all coffee (maybe they are right about the coffee they handle).
If you have some older coffee sitting around cold brew it. Fresh could brew is better but fuck it, give it to your friends if you are a super snob and they'll love it.
Mostly you need to find coffee's you really like and a brewing method that matches your preferences for taste, effort and clean up. The best way to make coffee is up to you. Some people don't like the distinctive pour over flavor, I think it highlights the difference between beans well. I really like aeropress at home for speed and cleanup time.
It's cheaper to not buy filters. You can tap and wipe most the coffee from the cone. You never run out of filters when you use a metal cone.
I've got a few different metal cones and don't really think there is and appreciable difference from one to the other. My roaster uses some a fancy $60 gold cone that he has to import from Germany, I don't think it's significantly better than a $15 ghetto filter.
Buy and try one of these and see what you think. http://www.amazon.com/HARIO-Stainless-Steel-Coffee-Maker/dp/B0040VIN18/ref=sr_1_2?ie=UTF8&qid=1460410193&sr=8-2&keywords=hariogoldfilter at worst you'll have a back up for when you run out of filters.
I don't really know all that much about coffee, but I'm always trying to learn a bit more. I think personal preference is way more important than Dogma.
If you want to get real serious about your grind you can buy a pricey spice grinder or pick up a used Bunn supermarket grinder off craigslist or ebay for about $150-200. You need a lot of space for Bunn grinder but it'd be a pretty dope household appliance. If you really want to get crazy you can put Ditting burrs in a bun grinder and even cut it down to make it take up less space as a hacking project.