A pre purchase inspection is a property inspection which you can have performed before you commit to purchasing a property. The reason to do this is to identify any issues with the property before you are locked into purchase.
Often an inspection of a property can be completed in an hour and give you an overview of issues the property may face in the future or problems that are currently present.
Yes, it is recommended you have a new house inspected as there can be a wide range of problems that need to be identified with the buildings warranty period.
If you consider the cost of problems that may be identified then a building inspection is a relatively cheap investment.
A pest inspection report will identify if there are any harmful pests in the building you are looking at purchasing. A pest inspection may not identify other building problems that may exist.