Headgasket?

I purchased a used subaru with an overheating problem which turned out to
be the head gasket. Went to the dealership, had them replace it. Still
overheating, took it back, they replaced it again. Over heating gone. 2 miles
up the road traction light and ABS brake light comes on. They say they're not
to blame and told me to just take the car. Fast forward 8 months later, my car
starts to have an oil leak problem, but i work full time and had no time to take
it into a shop, and the leak was external so i just kept adding oil. Well on my
way home from work im going up a hill and my rpms are staying super high
and not shifting properly. One mile later i hear a loud knocking noise, pull
over and my whole car dies. Open to the hood to my car being super hot,
smoking, and not starting. The engine would try to turn over but eventually
gave up 5 seconds later. Could they have messed up a seal? if there was
something wrong with my engine shouldn't they have told me? All parts and
labor are covered for 12 months regardless of miles. Does this sound like
anything they are to blame for?