I am not suggesting removing anything. Hearthstones, portals, and flightpaths can still function just as they always have to not mess with anyone’s immersion or gameplay. With that said… I would like to add another form of travel: Transrelocation.
Each time you visit an Inn, and speak with the Innkeeper (not set your Hearthstone), you create a geo-mapping location called a Transrelocation Point. Engineers will craft Translocators to sell which will act like a Hearthstone; however, there is a twist.
Activating your Translocator toy brings up a map, the same way a flight master map would appear. However, this map will show the entire continent and the locations of Inns on said continent. You simply click the Inn you wish to travel to, your location is locked in, and just like your hearthstone, but a bit more Sci-Fi, you are teleported to that Inn. Any Inn in the game regardless of which continent, or planet, you are standing on.
The device (toy) aptly nicknamed T.R.I.P. (Trans Relocation Interface Projector) will share a 15 minute CD with Wormhole generators and can be used by Non-Engineers. Think of it like Scroll of Town Portal meets Gnomish Engineering. No ridiculously prohibitive crafting mats so that it can stay CHEAP for sale, and everyone can have one.
Another iteration, should this one be successful would be called R.A.I.D. (Relocation Assistant of Indoor Destinations) and once you have discovered the Dungeon, Raid, or BG instance in the open world, this device will teleport you directly to the front door where you, and your party, can simply walk in, or 3 members can teleport and use the Meeting Stone to unite the party.
These are alternatives to travel, are NOT required, only make gathering and moving around easier for everyone. There is no tactical advantage, and in 99% of situations would encourage more open world content and the ability to pick an Inn close by to log out without Hearthing back to your preferred save spot.