Regarding Merge site pages,
This operation should be achieved manually by
- Opening the site page library with explorer.

- Copy the required site pages from the source site to destination site.
Regarding move a full Team Site,
Yes , you can do this operation by executing Export-SPWeb
and Import-SPWeb
cmdlets, but some points need to check before do this.
- Make sure the destination site have the same language of the source site.
- Make sure the destination site have the same template of the source site (Team Site).
- Make sure the features that activated at source site is already activated at the destination site.
To export site
Export-SPWeb [-Identity] "site url or GUID" -Path "backup file path"
For Export-SPWeb details : http://technet.microsoft.com/en-us/library/ff607895.aspx
To import the exported site
Import-SPWeb [-Identity] "site url or GUID" -Path "backup file path"
For Import-SPWeb details: http://technet.microsoft.com/en-us/library/ff607613.aspx
Note: Export-SPWeb
and Import-SPWeb
operation will overwrite the destination site with source site.