Google?
All the questions above can be answered with a very quick Google search.
The Merlin engines are said to be capable of 40 cycles without servicing, and Musk has stated that even the servicing after that is only a few replacement parts. They were designed with reusability in mind.
Benefits of reuse are huge, the 1st stage alone costs >$50M. They are aiming for rapid turnaround (a day or so), so that a huge saving from throwing the stage away each launch.
Currently trying to land on barge, intent is to return to launch site (except for F9H centre core which will need a barge landing)
Biting the hand that feeds IT
