Only arguable if you don't read the FAQ, which clarifies that the 'as if you hadn't made an attack' language is only there to indicate what BAB the followup attack uses.
That seems awfully high. Low level spells that are 'commonly' used, like invisibility probably shoudn't even require a spellcraft check to realize that it might pose a problem. Now he should make a spellcraft check to know what the duration of invisibility is, which would enable him to...
This one really made me laugh. On no, the poor casters are so weak. Fireball and Evard's tentacles are some of the nastiest spells for their level. Taking away pinpoint targeting is hardly gonna break full casters.
But basically it comes down to the nature of your group. Do you like...
Whether wood is particularly vulnerable to fire is a DM call. IMHO, wood isn't. The bonfire analogy works fine for me.
However, I would say the fletching is vulnerable. An arrow without fletching (or even worse, unevenly burned fletching) is not going to go anywhere near the target. So...
I concur with the halve damage then apply resistances concept.
As for making spell penetration checks, I'm pretty sure that you just make one check. Even if you target multiple people, you would only make one penetration check. You'd just compare that check to each individual creature's SR.
As was noted, the rules are a bit vague. I generally go with the caster level of the person who cast a spell into an item, as that makes the most sense.
However, using the minimum caster level is probably the most balanced method.
I see a lot of DM's (and the writers of the forgotten realms setting) who like to gimp knowledge (local).
Confining it to a specific area basically makes the skill nearly worthless, especially as the characters level up and begin traveling more.
Just compare it to the other knowledge...
The OP did it exactly right!
The rogues were aware of the PC's, and the PC's were not aware of the rogues. That's unequivocally a surprise round!
A spot check once the door is open was irrelevant. The rogues weren't hiding. A listen check to hear a stationary foe is debatable, but in this...
I'm pretty sure your average high level wizard has plenty of chances to shine
(maybe by ending encounters in 1 round perhaps?) besides getting the party across the raging river. Giving that opportunity to shine to the fighter who has 15 ranks in swim (cause his skill list sucks) doesn't seem...
Man, people are such party poopers when anybody proposes deviating from RAW.
I say go for it.
Adventures that REQUIRE an arcanist are already poorly written. While they're useful, arcanists shouldn't (and usually aren't) required. So knocking out a few spells is hardly gonna make or...
I have to disagree with this one. I think the gap must be 1 foot PER side. Otherwise it just gets silly. A 1 inch by 144 inch gap would qualify by your reasoning. Or you can go even thinner.