It's an expensive dodge, but the rental might have been his way of getting around NJ gun laws. There might have been no intent to use the house other than for this.
I wonder if they were hiding out. Getting a gun illegally in NY/NJ is pretty easy if you have lots of money.
Maybe his plan was to light off the bombs then scoot to Roanoke.
So many other “residents” of that address on Patterson Ave. have been able to acquire VA drivers licenses and firearms and get them back to NY & NJ?