1. I don't have this module, so I can only guess the module's code.
In the module's class file (core/common):
$weekago = strftime("d/m/Y", date() - 60*60*24*7);
An then, in the SQL code that retrieves the PIREPs, add this:
AND submitdate > '$weekago'
2. Here's an example for the most flights per pilot for this month. Variables might not be correct in the table I'm afraid, I'm doing this quickly.
<table>
<?php
$month = date('m');
$year = date('Y');
$mostflights = TopPilot::top_pilot_flights($month, $year, 5);
foreach($mostflights as $flight){
<tr>
<td><?php echo $flight->pilotid;?></td>
<td><?php echo $flight->flights;?></td>
</tr>
}
?>
</table>
Both untested, give it a go.