We had a similar problem importing from an old (non CiviCRM system) and I wanted to make the old membership numbers the Contact ids on the new CiviCRM system. Fortunately membership numbers 1 & 2 were not in use so no clash with the initial admin and organisation contact records. There were some gaps in the old membership numbers and I was also quite ...
Was this all driven by wanting to move from Drupal to WordPress? If so, you can do this at the database level since most of Civi's data is independent of the CMS.
Since Imran is on CiviCRM Spark, I had a quick look at the issue. I think it was caused by the field mapping, where the import was trying to import the "Contribution Status", but there wasn't a status for "paid out", causing the import to fail.
So I changed the import mapping to ignore the import status (since the file only completed contributions), and it ...
We use the Form Processor at a few of our clients for scenario' s like yours. In most cases we use this in a configuration with CiviCRM on another server and outside traffic (including the Form Processor API request) coming in through CiviProxy (https://docs.civicrm.org/civiproxy/en/latest/).
For this we use the CiviMRF framework (https://github.com/...
You can create profile with the fields you want to updated and then use bulk update action from search action to update multiple records.
Importing contact and its details involves more efforts unless you don't want historical data of the contact like contribution, event registration, activity etc. Would suggest to use the same database for your wordpress and clear CiviCRM cache.
The menu items position may differ based on how old is your CiviCRM compared to newly fresh installed CiviCRM but ...
As I understand your question you want to import existing data with the form processor. Is that right?
If so it is possible because the form processor creates an API in CiviCRM and this API can be called with REST from external systems.
The API entity is FormProcessor and the action is the name of your form processor.
You need some bit of custom ...