Sage's mistakes

[Dyslexic]

Someone tell me that the Sage sometimes wrong.
Is it true?
Can you tell me which Sage Advice answer are wrong (because contradict by FAQ or Errata or something esle)?

thank you

[Curmudgeon]

The original Sage/author of the FAQ was Skip Wilson, who also wrote the "Rules of the Game" series of online articles. Skip had a tendency to mix in his house rules with RAW answers, often without distinguishing them. Andy Collins took over and removed some of Skip's more dubious answers from the FAQ document without notice. Mike Mearls was "guest sage" for a week, and came up some truly atrocious answers regarding the Factotum. Here's a sampling of some fairly obvious errors. There are dozens more.

You might be confusing Quick Draw with the ability of any character with a base attack bonus of +1 or better to draw or sheathe a weapon as a free action as part of movement (PH 142)

From page 42 of Player's Handbook:

Draw or Sheathe a Weapon
Drawing a weapon so that you can use it in combat, or putting it away so that you have a free hand, requires a move action.
...
If you have a base attack bonus of +1 or higher, you may draw a weapon as a free action combined with a regular move.

Sheathing is never a free action.

Can a wild elf gain a dragonmark available to elves (such as the Mark of Shadow)?
No. In the ECS, subraces are not eligible to select a specific dragonmark associated with the parent race.

The term "subrace" is never used in Eberron Campaign Setting, so this is pure malarkey.

Unspent inspiration points are replaced when the factotum returns to his full number of points once an encounter ends.

The actual rule (Dungeonscape, page 16):

At the beginning of each encounter, he gains a number of inspiration points determined by his level (see Table 1–1).

If the characters have a minute or two to catch their breath and rest, assume that the last encounter has ended and all per encounter abilities refresh.

Again, see the actual rule above.

1. Can a factotum spend more than one inspiration point on cunning strike to gain more than 1d6 points of sneak attack damage?
2. Can a factotum of 19th level use cunning brilliance to emulate a rogue’s sneak attack ability?
Answering your questions in order:
1. Yes, you can use multiple inspiration points to gain additional sneak attack damage.
2. It’s reasonable to assume that sneak attack is an extraordinary ability.

1. From Player's Handbook, page 313:

stack: Combine for a cumulative effect. In most cases, modifiers to a given check or roll stack if they come from different sources and have different descriptors (or no descriptors at all), but do not stack if they have the same descriptors or come from the same source (such as the same spell cast twice in succession). If the modifiers to a particular roll do not stack, only the best bonus or worst penalty applies.

Cunning Strike has no exception to this basic stacking rule. Every modifier to a damage roll from the same source (Cunning Strike) must overlap, not stack.
2. From Player's Handbook, page 180:

Natural abilities are those not otherwise designated as extraordinary, supernatural, or spell-like.

Sneak Attack is undesignated, so it is by default a natural ability, not extraordinary. It's not reasonable to assume something that directly contradicts the rule.