Now as for taking 10 on a spot check.
Reading the example in the PHB (not contained in the FAQ) the strong implied meaning is that you are "being careful" when taking ten.
So I have difficulty saying that you can be careful when making a reflexive roll (like the normal spot check).
On the other hand if you are using the focused spot attempt - the standard action version I can readily see you being "careful" and taking 10.
The example of the guards and assumption they are taking 10 on spot checks also fits in this interpretation since, IMO, if they are "guarding" then they are not using the "reflexive" spot check but instead an "active" spot check because they are actively looking for something. Still can't take 20 without getting into trouble because that means they are looking at a 5 ft square for 2 minutes.
Reading the example in the PHB (not contained in the FAQ) the strong implied meaning is that you are "being careful" when taking ten.
So I have difficulty saying that you can be careful when making a reflexive roll (like the normal spot check).
On the other hand if you are using the focused spot attempt - the standard action version I can readily see you being "careful" and taking 10.
The example of the guards and assumption they are taking 10 on spot checks also fits in this interpretation since, IMO, if they are "guarding" then they are not using the "reflexive" spot check but instead an "active" spot check because they are actively looking for something. Still can't take 20 without getting into trouble because that means they are looking at a 5 ft square for 2 minutes.