Sentences

1. Most of the dead would have been carried down the road from Durrington.
Does "would have been carried" mean "could have been carried"
If I'm almost certain.?
2. Transporting such enormous stones was a remarkable achievement for the time.
Does "for the time" mean "in that time"?
3. It was contrary to what you thought.
4. It was unlike any other human archeologists had ever seen.
Are "unlike" and "contrary" adjectives or prepositions?
5. Travelling to Flores involved sea crossings of up to 24 kilometers.
Does "involved" in this sentence mean "caused"?