Yes. OpenOffice is perfectly legal.
Yes. OpenOffice should be available in the repository for Linux, and is available on OpenOffice's website for Windows.
OpenOffice 2.4.0 was released on March 27, 2008.
You can have a maximum of 2292 columns in an OpenOffice spreadsheet.
Jambo OpenOffice was created on 2004-12-04.
Only you know which operating system your version of OpenOffice is installed on. The version of OpenOffice you're using, can be found by - opening any document, clicking the 'help' button, and selecting the 'About OpenOffice' option.
There should be no problem running OpenOffice on Windows 10 and OpenOffice has always been able to read Word files (there may be problems writing some of those files back out as the same Word format due to licensing issues, but if you intend on switching to OpenOffice you will be saving as OpenOffice format not Word).
No - OpenOffice does not require registration of any kind.
OpenOffice is developed by developers all around the world under the guidance of Oracle Corporation.
No. When downloaded from the official website, all components of OpenOffice are safe to use.
Just open it as if it was an OpenOffice document. OpenOffice will read MS Works documents quite happily, and you can either save them as OpenOffice or MS Works formats.
you can not.