You can always negotiate who will pay for inspections, but it is standard in Vacaville or the buyer to pay for them. County transfer tax and any government retrofit or repairs mandated by state law are generally paid for by the seller.
Most pest reports classify conditions as Section 1 or Section 2 items. Section 1 conditions are those which are "active", or currently causing more damage to the property. Section 2 conditions are those which are not currently causing damage, but are likely to if left unattended. A typical Section 2 item is a plumbing leak where the moisture has not yet caused fungus decay.
As stated by Rockin Realtor, the VA requires any section 1 and section 2 items found during the inspection to be paid for by the seller, HOWEVER the inspection itself can be paid for by either party.
The cost to do the required repairs for the clearance can be paid by either party (buyer or seller) which is negotiable.
Can you ask the seller to tear it down? TEAR WHAT DOWN? a infested structure? yes.....