I have a question for the rest of the group. What do you think of players using very off-the-rails tactics? Things like burning down the adventure location in order to kill the enemies inside since they don't have hostages or a fragile macguffin. Do you like this because it can create an interesting battle, or hate this because it ruins the hard work you put in building the adventure location?
I have typically run PFS scenarios where there is set mechanism to handle this type of thing. However, should a group of PCs decide to pursue a course like the one described above - burning down a building to destroy a group of enemy NPCs - I would offer them the opportunity to design and detail such a plan.
Working with them I would point out areas where the plan could fail and leave them with a destroyed building, but very alive and very mad enemies. If they wish to further improve the plan, I set a time limit for the plan in game terms (i.e. how long their window of opportunity is within the context of the campaign/adventure)
If they make it through to a final plan, I would then explain "tit for tat" and upon receiving agreement that what is fine for the NPCs is also fine for PCs allow them to execute the plan. I would then shortly afterward execute a similar plan against the PCs undertaken with the same depth and level of precision.
I don't know if this makes me "like this because it creates unique and interesting situations" or if "it ruins my wonderful plans". It does reinforce the natural consequences of escalations and demonstrates checks and balances to the PCs.