What state are you in? Laws vary a bit state by state.
You have a copy of a 30 day limited powertrain warranty so I would think this should cover any engine/transmission fautl but it can be very difficult to push an issue like this.
The thing now is figuring out what any alleged engine issue may be. The odds of it being a cracked head or block are very very slim. That diagnosis is made many times by someone who does not know the answer to the mechanical question at hand.
That diagnosis may often be given when overheating is involved. A compression test could be done to verify any head gasket or piston ring problems.
A twisted frame would not be covered and it’s possible for a vehicle to ride fine while in this condition. A 4 wheel alignment may show something or it may take a visit to a body shop that is equipped with a frame machine.