You need to add another label for line 10 in the modules.price_notify/pricenotify.tpl
The label is:
lbl_send_your_email - Please enter your e-mail in the box provided to be notified of any price changes
You also need to change line 19 from <TD class="FormButton">{$lng.lbl_send_price_your_email }:</TD> to <TD class="FormButton">{$lng.lbl_send_your_email}:</TD>
You forgot to add this to the labels, otherwise you will get a smarty error.
Also the check_options.tpl is wrong at line 143, you have put var link1 = "<a href='price_notify.php?productid={$product.product id}&price=$product.taxed_price&productcode="; and it should be var link1 = "<a href='price_notify.php?productid={$product.product id}&price=$product.taxed_price&productcode=";
No space between the product and the id, you have {$product.product id} and it should be {$product.productid}