I don't believe I ever said it was, but using COP and your familiar's Commune would allow you to establish the general location and general defenses with a few day's worth of effort, which is a great benefit.
I think there are plenty of ways to get that basic outline. Ultimately, if you can't find the general location, a lot of work went into designing the Dragon and its lair for not much real purpose - adventure notes make lousy wall hangings, even with a nice frame

Incidentally, I believe one can take 10 on the Int check with COP, which reduces the risk of losing spellcasting somewhat.
That mitigates the issue quite nicely, and returns the spell to "usable". I'm not sure of the designer's intent, but a penalty that substantial should not be possible for non-abusive use of a spell, and it's consistent with Take 10 on spellcraft when crafting magic items.
The one in the PHB, I imagine.
I think Polymorph holds the record for "most errata'd spell" (and is not content to rest on its laurels...) The SRD version at http://www.d20srd.org/srd/spells/polymorph.htm provides as follows:
SRD said:This spell functions like alter self, except that you change the willing subject into another form of living creature. The new form may be of the same type as the subject or any of the following types: aberration, animal, dragon, fey, giant, humanoid, magical beast, monstrous humanoid, ooze, plant, or vermin. The assumed form can’t have more Hit Dice than your caster level (or the subject’s HD, whichever is lower), to a maximum of 15 HD at 15th level. You can’t cause a subject to assume a form smaller than Fine, nor can you cause a subject to assume an incorporeal or gaseous form. The subject’s creature type and subtype (if any) change to match the new form.
Upon changing, the subject regains lost hit points as if it had rested for a night (though this healing does not restore temporary ability damage and provide other benefits of resting; and changing back does not heal the subject further). If slain, the subject reverts to its original form, though it remains dead.
The subject gains the Strength, Dexterity, and Constitution scores of the new form but retains its own Intelligence, Wisdom, and Charisma scores. It also gains all extraordinary special attacks possessed by the form but does not gain the extraordinary special qualities possessed by the new form or any supernatural or spell-like abilities.
Incorporeal or gaseous creatures are immune to being polymorphed, and a creature with the shapechanger subtype can revert to its natural form as a standard action. "
So nice physical stats, but no regen, for example. Other forms (or spells) could clearly be used to augment the fighter, though.
If I have a party, I might as well make use of the fact. Using Planar Binding to get substitutes for a party is possible with enough work, but I see no reason to do extra work as my contention is not that the wizard can solo dragons, but that wizards are more powerful than fighters, in that they can contribute more to combat and non-combat situations.
So long as the result is an enjoyable game for all participants, I'm not too hung up over a perception of some power differential. The wizard is unquestionably more versatile, and I agree with the Pathfinder approach of beefing up the warrior types with more additions than the spellcasters got. I'd also like to see non-spellcasters get some class abilities that are directed to non-combat contributions, ideally choices of abilities which cannot be traded in for more damage/to hit bonuses, etc.
I can imagine a few things that would stop the dragon from retreating into the Solid Fog and lobbing out acid, such as a polymorphed fighter charging into the fog. Alternatively, Resist Energy.
The fighter can't move any faster than the dragon, though. Resist Energ would help, although this becomes a question of the dragon's options for stalling for time. 10 minutes per level practically means "run away and come back later" if he wants to stall, though. I would, however, expect the team working together to defeat the dragon, so I'm not really all that disappointed if the party wins. If the wizard abandons the party to take it on by himself, that's a concern.