Not really "quest" questions, but oh well.

First, I heard the skill trainer (that unlearns your skills) charges double every time you unlearn. First 5000 gold, then 10000, and so on. Is this true? And if so, does the gold just vanish? I'm assuming that even with infinite herbs/ore/gems, you're still limited to all the items in the world + all the money of each shopkeeper, so does it ever run out, and is the skill trainer really that expensive?

Second, what exactly does finishing "Into the Bandit's Den" lock you out of? This is what I figure so far, so tell me what else it locks you out of, or if anything on this list can still be done afterwards:
-Mindread Christopher while guarding for a stat point.
-Start and complete the quest "Couple Trouble."
-Start and complete the quest "An Axe to Find."
-Mindread Tagos for a stat point.
-Utilize Martis' services as a shop dealing mostly in rare/magical-class items, and mindread him for a discount.
-Mindread Ragnar to make the key spawn in the Temple of Doom.

Are the following things also not possible?
-Pick up the weapons the four Lv10 bandits are fighting over.
-Temple of Doom and Jagon bounty.

I'm also guessing that if you mindread Martis to finish the quest, he won't be present in the Bandit Camp, even if you don't turn in the Into the Bandit's Den mission, right?