I think @Randy E. gave you great advice and I was going to reitterate the same thing. If you have a no pets policy you should have evicted when you found out they brought in a dog. They already signed off on the lease that states there are no pets allowed, therefore they are breaking the agreement. Also, it is your property whether they installed an alarm system or not. If you give proper notice, have proof of this, and then enter when you state you are going to, I would think they would be held liable for any charges incurred on having the alarm go off. It's their responsibility to leave the house unarmed if you told them you would be there, or to be there themselves if they feel necessary.
I would double check your state laws, and check to see if they have renters insurance (my guess would be they don't) because you would most likely be held responsible for putting them up in a hotel during the tenting, but I agree on holding off until after they move out... something that will hopefully happen in the next 30 days! Best of luck!