Distances
If you had the appropriate neck, you can get most non-raid zones within 2 or 3 zones of the zone you neck to. So I compiled a quick list of how far the farthest zones are from places you can neck to. I may have missed some shorter routes. Before that, though, is a list of gate items I didn't include.
DOES NOT USE:
Any deity neck.
Amulet of the Cult Voice (Newport Sewers, NEC only)
Book of the Archmagi (North Badlands, int caster only)
Redsun Girdle (Red Sun Peaks)
Swirling Portal Staff (Faentharc Woods, WIZ only)
3 Zones Away----------------
Blackburrow
Catacombs of Elthannar
Cyrtho Malath
East Badlands
Everchill Caverns
Halas
Halls of Misery
Hate's Fury, The Scorned Maiden
Highkeep
Kedge Keep
Keep of Mielech
Mistwoods
North Kaladim
Red Sun Peaks
Ruins of Nagthilian A
South Badlands
Surefall Glade
The Arena
The Deepshade
The Grand Library
West Badlands
4 Zones Away----------------
Fire Grotto
Heartland Plateau
Lair of Paw
Mielech's Lair
North Badlands
Red Sun Mines
Ruins of Nagthilian B
Shrouded Isle
Tunnels of Lasanth
Valley of Erimal
West Freeport
5 Zones Away----------------
Emberflow Caverns
Heartland Undercaverns
North Freeport
Ruins of First City
Ruins of Nagthilian C
The Warrens
6 Zones Away or More------
Nothing!
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This should be a good jumping off point for deciding on something like the usefulness of new gate necks. So lemme start it!
We have eleven 4-away zones and six 5-away zones. There are some specific zones that would greatly benefit from a gate neck and largely demote the 4-away and 5-away zones to at most 3-away zones.
(1) Including the Redsun Girdle (or some other Red Sun Peaks port) would demote Emberflow Caverns, Fire Grotto, Red Sun Mines, Tunnels of Lasanth, and West Freeport to 3-away or less. North Freeport and Ruins of Nagthilian C would become 4-away zones.
(2) Either an Erimal or an Erudin neck would demote Ruins of First City, Shrouded Isle, The Warrens, and Valley of Erimal to 3-away or less easily. Oddly enough, this works most efficiently with Mistwoods being the port-to location.
(3) Interestingly, a North Badlands neck, however weird, would demote Heartland Plateau, Heartland Undercaverns, Lair of Paw, and North Badlands to 3-away or less.
Between all of these, there would be three 4-away zones: Mielech's Lair, North Freeport, and Ruins of Nagthilian C. Everything else is already 3-away or less from an existing gate neck or would be serviced by these 3. Considering the 3 zone nature of Freeport, Miel ABC, and Nag ABC, I don't see this as a problem. Also of note: Each of Red Sun Peaks, Mistwoods, and North Badlands (the 3 zones that I'm discussing) are directly accessible through both wizard and druid ports.
So, this brings up some questions:
(1) What would more gate necks be intended to provide the people who want them?
(2) If they are for making zones easily accessible alone, is it OK to make them go to places like NBL and RSP?
(3) Do wizard and druid ports sufficiently cover the accessibility of the more remote zones?