Yes, you can use Export Filters to do both of the tasks you outlined.

1. Create an Export Filter
First you need to create an export filter. To do this, select Tools > Export Management > Manage Export Filters. Add a new filter and in the General tab make sure Filter on All Surveys and Filter on All Taxonomic Groups are specified. Click OK and you're done creating your filter.

2. Export All Data
To export all of your data, select Tools > Export Management > Export Using Filter > Name of your filter. Select the appropriate Export Type (NBN Access Database zipped is recommended) and specify an export destination. Here's the important bit: select Export all records for filter. You can at this stage also transfer custodianship of the data by ticking the relevant box; this will allow the receiving party to edit the data but will in turn disable you from editing the data. When you're ready to export, click OK.

3. Export only additional or changed data
Go through the process as above, but instead of selecting Export all records for filter, select Export records changed since. Recorder will have remembered when you did your last export (the one you did in step 2) and will automatically fill in the correct data for you.

Hope that's of help.

Charles