When instructed to "Repeat this Power", do you have to obey the origin/range/target land restrictions?

When instructed to "Repeat this Power", do you have to obey the origin/range/target land restrictions?

Only if it doesn't tell you where to Repeat it. If a Repeat specifies where to use it, you obey those instructions, ignoring the original Range and Target restrictions (p. 19) and using the same origin land (for the rare cases where the Power's effect references that land).
For example, "The Land Thrashes in Furious Pain" could be Repeated on an adjacent land without Blight.