Yes. (even if there's an exception, this is a good way to think about it)
Depends on the rules code. Always delayed in FED; sometimes delayed in OBR and NCAA
In general this is correct, but the specifics depend on the rules code.
For example, in FED, there's a minimum one base award form the location of the OBS. So, if the OBS was actually before second, (e.g., if F6 was standing on second and R1 had to slow down to approach) then the minimum award is second. In OBR, there's only a minimum award if the runner is being played on (and he's not in this scenario.
And, the umpire should think of OBS as a *distance* (e.g., one or two strides) and must consider post-OBS play to determine the ruling. For example if F9 bobbles the ball and R1 now tries for home -- if he's out by only a stride or two, the umpire can award home; if he's out by "a lot" then the out stands.