Nightly automatic updates / downloaded script questions

I'm currently configuring one of my Keyword Tracker groups to automatically update using the group settings, and have a couple of questions about how the automatic update happens:

1. Does DigitalPoint make a request to this script on my server? Will I have to explicitly allow these requests?
2. Do I have to add GET variables to the end of my script url in order to configure it to update the information I want?
3. Does it update the Keyword Rankings, the the Page Rankings, or both?
4. Is there any way to have the tracker update less frequently (Once per week)?

Also, after downloading the script, placing it on my server, returning to the settings page to update the script location, and trying to save, I get an error message:

Can't use function return value in write context in <file-location>.php on line 85
​

The offending code seems to be this:

foreach ($all_keys as $key => $val)
{

if (empty(trim($val)))
{

unset($all_keys[$key]);​

}​

}​

And replacing it with this code eliminates the error:

foreach ($all_keys as $key => $val)
{

$tval = trim($val);
if (empty($tval))
{

unset($all_keys[$key]);​

}​

}​

Is the script broken? Or is it some issue on my end?

EDIT: Seems like empty() is a language construct, and attempting to pass a function to it doesn't work on servers running PHP versions before 5.5

 

Thanks for the info. The server I'm using is running PHP 5.4, and the reason I was wondering about weekly updates was because I was a bit unclear about the usage quotas for Google's custom search API. I plan on tracking a lot of rankings using the keyword tracker, and I was worried that nightly updates might push me over my quota. However, it seems like the quota for this API is reset daily, so nightly updates aren't a problem.

Again, thanks for the info, and the timely response.