So how could chapter two be different?
1) The terrain type needs to roll out and change gradually from wherever you are. It should be gradual, so that you hardly notice that the terrain is changing...but it is.
After walking for 5 minutes, you might see a new type of tree, a new animal or different rock types which will become more and more common the further you go.
This would get rid of the fake transition "Oh i'm in a snowy area...go through this magic door and i will be in a barren and scorched wasteland".
There should be almost no restrictions on adventures. If we want to walk through the lake...let us. It's only a game at the end of the day.
You could always pretend we have a magical air bubble around us, lol.
Let us scale that big steep cliff and take a screenshot at the summit.
2) The creatures need to be arranged differently.
It's great to have a mixture of creatures of all levels and types spread over the continent. This arrangement should be sparse but varied to the extreme.
It also needs to keep the current arrangement of having large pockets of same type and same level creatures (like a huge bunch of Charr or other tribal types).
Why? What are the advantages to this arrangement?
Basically, when you are exploring the massive open areas, you will want to pick off the easy enemies and avoid that big old nasty Tyrannosaurus who would eat your whole PUG and ask for seconds.
"John, whatever you do, don't aggro any of the big ones!"
"Oops!"
It adds tremendous amounts of emotion to the gameplay from the first time you step outside. As it stands now, upon completion of the game, alot of areas are basically out-of-bounds because they are so easy and boring.
Lets have level 3's, level 10's, level 20's etc scattered all over with large pockets of certain levels also dotted around.
Throw in a few "near-impossible" level 50 hydra's wandering solo through the wilderness.
Areas of X mob of X level become almost synonymous to a particular area.
Also have "alleyways" of no enemies, just enough to squeeze through without aggro. This eliminates the "perceived need for runners" (as you said you wanted to do in one of the FF interviews).
Pete: Where's the area of level 8 grawl?
Mike: Head north for ten minutes, take a right turn after the bandit outpost, dodge past the scaly mammoths because they are too hard for you and they should be just before the icy mountain...can't miss it!"
Pete: Thanks!
So what i'm basically saying is, open up the map. Get rid of the trails, blocked paths etc. Make the world bigger.
Get the vegetation and terrain arranged into a gradual progression arrangement. I don't want my adventures to feel like i have just stepped outside my house on a rainy day. Dry and warm > Wet and cold. Gradual please Anet

Mix up the enemies. Add a few solo godlike bosses... "OMFG RUUUUN!!!!1one."
Make groups of enemies for all players in every corner of the map.
(Level 5 hydra's, level 15 centaurs, level 30 undead, mixed levels of X)
Here is a quick Picasso impression of what a typical zone (if we will still have zone...if not "portion" instead) will look like.

One coloured bunch might be level 20 grawl and the next might be level 5 trolls. Everyone has access to many monster types and levels in the same zone and the zones also have solo monsters of varied levels for EVERYONE who wants to go solo.
Anybody can go from point A to point B without any assistance and on the way they would be able to pick their fights at their choosing.
The possibility of bumping into a big bad boss is also there for the people who are thrill-seekers...or just clumsy.
3) Mission zones/towns.
They can be arranged on the map in order of first being first...move onto the next one, etc.
The difference is, you can bypass every single mission, if you choose to do so. If i wanted to go to Glasgow, i don't have to go through Hull on my way there...i can go around it.
The only problem with this scenario is that some people would deliberately go to the last mission and not have the skills and experience needed for that mission, therefor ruining a good PUG for the rest of the team.
Easy solution is to implement a reward system that makes the attaining of skills through quests more worthwhile. A snowballing reward system would be good. The cash and item rewards build up so greatly that it simply isn't a rational choice to avoid them.
If Mr X skipped to the last mission, he would only get 100 XP and 10 gold for completion....not worth running all day for and he still would be left without his skills.
Another idea would be to have all skills available at the first city instead of the last. If the monsters are scattered, there is no need to have skill attainment still based on an old linear system.
A flaw in this idea would be that farmers could buy all their skills immediately.
Solution - when chapter 2 comes out, invent "advanced skill points".
You would gain XP still, but if you gain 100 experience, it would infact be 100 of the original experience and 100 experience for an advanced skill point.
You'd effectively have 2 experience bars in one. One for the old classes and one for the new. << needs work on this bit maybe

Just doing my bit to throw some ideas on the drawing board while taking into account other peoples ideas i have seen around.