1) Is there a way to prevent advertisers from accessing the reports from the front end?
At this point you can´t. Anyway you can edit the advertiser profiles and there uncheck the reports.
2) Is there a way to disable email reports / and remove email report selection preference from advertiser registration?
Edit your ijoomla_ad_agency.html.php and remove this (line line 2295 aprox.):
<tr>
<td width="10%" nowrap>
<?php echo _JAS_EMAIL?> <?php echo _JAS_OPTIONS ?>:
</td>
<td>
<table align="left" border="0" cellspacing="0" width="350">
<tr>
<td width="20">
<INPUT class="formField" TYPE="checkbox"
<?php if ($adv_row->email_daily_report=='Y') echo 'checked' ?> NAME="adv[email_daily_report]" value="Y" >
</td>
<td width="120">
<?php echo _JAS_DAILY ?> <?php echo _JAS_REPORT?> </td>
<td width="20">
<INPUT class="formField" TYPE="checkbox"
<?php if ($adv_row->email_weekly_report=='Y') echo 'checked' ?> NAME="adv[email_weekly_report]" value="Y" >
</td>
<td width="180">
<?php echo _JAS_WEEKLY ?> <?php echo _JAS_REPORT?> </td>
</tr>
<tr>
<td>
<INPUT class="formField" TYPE="checkbox"
<?php if ($adv_row->email_month_report=='Y') echo 'checked' ?> NAME="adv[email_month_report]" value="Y" >
</td>
<td>
<?php echo _JAS_MONTHLY ?> <?php echo _JAS_REPORT?> </td>
<td>
<INPUT class="formField" TYPE="checkbox"
<?php if ($adv_row->email_campaign_expiration=='Y') echo 'checked' ?> NAME="adv[email_campaign_expiration]" value="Y">
</td>
<td >
<?php echo _JAS_CAMPAIGN_EXPIRATION_NOTICES ?> </td>
</tr>
</table>
</td>
</tr>
Best regards,
Author