Do all imports require credits in PlaceMaker?

No. If you are a PlaceMaker subscriber, you can enjoy worldwide unlimited OpenStreetMap imports (roads, buildings, paths, rails, water, trees) without using any credits.

If you have a free PlaceMaker Pay-As-You-Go license, or if your subscription has expired, all imports will require at least one credit.  The amount of credits required depends on the amount of data being imported as well as the source of the data.