for the second problem i think a solution is to change line 130 in druglab.php
$exists = $db->query("SELECT `type`,`usrID` FROM `materialsowned` WHERE `type`=".$cct['dID']."");
with this line
$exists = $db->query("SELECT `type`,`usrID` FROM `materialsowned` WHERE `type`=".$cct['dID']." AND `usrID`=".$_SESSION['userid']."");