Having problems with OpenLayers in Drupal 7
The errors you are seeing, are mostly harmless. PHP on your server is configured to be very strict, which is a good thing, and the Openlayers have previously not been very strict about the coding standards.

I haven't looked specifically at the errors you are seeing, but when I've seen similar issues, I've almost always found the problem fixed in the dev version.

As no-one is actively maintaining the module, there is not likely going to be  a new release any time soon. You're best option is probably to try dev, and report the issue if that doesn't help.

The ugly workaround is to turn down strictness on the error reporting on your php install.

You can also give the less feature rich but newer Leaflet module a try.