A big shift to Paludal Caverns up until 20ish. Unrest is still great for DS PL since the undead generally won't flee at low health. Outside of that I am not familiar with 20 to 50 in Luclin
Somewhat, yes. The older zones typically become Plvling hotspots. As Mashef says, Paladul becomes the new 1-20 spot. Guk generally remains the 20-40 spot, although you'll have to contend with plvlers there too. Velks stays the 40-50/55 spot, and then GE becomes the 50+ spot. There are obviously other paths, but Zone EXP Modifiers, mob level stratification, and mob density all favor the above zones. If they just made outdoor zones worthwhile EXP'ing in, Luclin would be so much more fun.
Hollowshade Moor is a nice zone for lvl 20-30 , lotsa mobs to kill Grimling forest has a bad landscape, but in the tunnels and grimling camps it's a nice zone for 30-35. Acrylia Caverns is indoor zone populated by grimlings lvl 36 at the entrance to lvl 55 in the Inner Acrylia. Can be pulled single/double without a CC. 2-3K pp worth of merchant-sellable items per hour. Can be soloed up-to lvl 60 for some nice exp. Back in the old days of PoP it was still a contested place to farm.
I'm planning on leveling my vah shir in Luclin only. I prefer some of the quieter zones to level in and stay away from a lot of the drama.
Kennels in Chardok is still best exp spot 55-60 or for AA grinding in Luclin.. Mob density and respawn time give it a clear advantage.
Yes, very few people will be in the older zones except boxes/bots/afk PLs. Someone mentioned Guk earlier, but already since Velious is released, everyone goes to ToFS now, not Guk. I have gotten 1 guk group since starting my last 2 characters, and I had to make it. It's just the natural progression on a progression server! People will be in Paladual, ME, Grieg's End, AR, every where else that is new. It will be a ton of fun though, Luclin is one of my favorites.