Nice concept, but here's some comments:
First Versatile Profession should only give one Profession skill each time. Choosing two makes this straight up better than Versatile Performance, and the Explorer a better skillmonkey than the Bard, when it has no reason to be.
Second, Market Baron is just bad. Gaining 60% percent more on what you sell means you sell stuff for more than you would spend to buy it. This means you could sell a +5 weapon to one guy, buy a +5 weapon from a different guy and have a net profit. Don't mess with WBL, or at least don't mess with it so much, it breaks the game.
I can understand the part about cheaper magical properties for improvised weapons since you might want a +5 shovel and +4 fishing pole and some +4 forks to throw at people, but I think this would be best as part of Equipment Training, just have Improvised Weapons he uses gain a scaling magical bonus for minutes a day, similar to what paladins can do with Divine Bond, instead of Weapon Training.
Also Market Baron just doesn't mesh with the rest of the flavor for the Explorer. He's a forever wandering traveler, but SOMEHOW he is also a renowned salesmen? What? Also I'm pretty sure if you enchant an improvised weapon with weapon enchantments, it stops being "improvised" and becomes a weapon.
Favored Movement, Terrain mastery and Terrain Dominance all come too soon. You only have one Favored Terrain so you can't actually choose your movement, mastery and dominance. And this keeps going until twelve level. Also Terrain Dominances are too powerful for fourth level, they were designed for tenth level characters.
Suggestion: Give Favored Terrains faster than a Ranger, maybe two at first level and one more at third and every three levels. Bump Terrain Mastery to 4th level and every four levels. That way you'll have a choice of three terrains to to master. Pusho Terrain Domince to 9th or 10th level and every four after. That way you'll have an actual choice of whcich terrain to dominate.
Gear Upgrade just goes from 90 gp to 65,610 gp. Might think of having this increase gradually with levels? Also, a nine-fold increase would be 810gp. 65,610 is a seven hundred and twenty nine-fold increase. And finally, this ability is broken as all hell. Seriously he can produce a headband or belt of +6 to one attribute or +4 to all three, every day he is not adventuring and outfit the party for free.
My recommendation would be to diminish the daily amount a lot, this should be useful to get a potion or scroll or wand with only a few uses left or a cheap one shot item, not to outfit an army in magic weapons and armors in a few days. Also put a sentence saying that after a few hours unused or permanent items just seem to get lost or broken, even if someone was wearing them. Maybe lost in the Pathways or sent back somewhere so other explorers can find them when rummaging.
Exotic Ritual, once again straight up better than what a similar class gets, in this case, the Skalds Spell Keening. Make it a full round action unless the spell has a longer casting time and either restrict the classes it can cast from or limit the spell level to sixth or maybe seventh, to keep it close to the factotum.
Master of All Lands, why does this gives the final favored movement? Why does the explorer gets all favored terrains, all terrain masteries and all terrain dominances but not all favored movements?
Being of All Terrains. Wow, this is broken. You basically gain at least +2 favored enemy against everything, a boatload of spell like abilities, lots of improved senses, movement types, bonuses to a bunch of skills, immunity to fatigue and exhaustion, Fire and Cold Resistance 20, Dr 2/Adamantine, and his attacks count as good, lawful, chaotic, evil, silver and cold iron. This would be broken as a capstone, as a 15th level ability it's just nuts.
What I suggest is:
Being of All Terrains, spend some time to retrain a Favored Movement Terrain Mastery or Terrain Dominance to a different Favored Terrain, this should be as fast or faster than actual retraining rules, maybe even faster if you can get a guide or teacher that also has that favored terrain to tach you.
And keep the progression Favored Movement, Terrain Mastery and Terrain Dominance going instead of stopping at random levels.
Pathways:
The Veil: Why does this create undead? An Su way to cast Resurrection is already good enough, you don't need to turn all the party into undead on top of it.
Wanderlust Pass: What is the action to open the passageway? Geas doesn't have a saving throw but it does have a en minute casting time, if this has a smaller casting time, use a different spell, with a saving throw instead. Also area of effect compulsion has a 90% chance of screwing the party, either allow party members to ignore the effects or give the explorer knowledge of where allies wind up so he can gather them again. Just allies, using this to scatter enemies and then taking them out one by one should necessitate some other way to find them.
Unassuming is cool, but Bliss is awful. He can grant multiple wishes or miracles with a week long ritual, without cost. Wish and Miracle are already broken spells, no need to make the thing even worse. If you're dead set on this capstone add that it can only grant the wish or miracle to one traveler per trip and that it can't grant wishes/miracles to the explorer since he already obtained his bliss.
I'll throw in some Forbidden Path ideas later. Do you mind if some are based on MtG?
This concept reminds me a lot of the
Divine assessor prestige class
and the Dark Delver.