I am not sure what your question is this time around. You write...

The above works with the template but I'm not sure if I'm missing something.

If it works, then you are not missing anything. Your template code is, though, a bit confusing. You have typed (perhaps, a typo) --

<select name="school_id"><option selected value="1"><option selected v
+alue="0">Select<tmpl_loop name=options>
<option value="<tmpl_var name=school_id>"><tmpl_var escape=html name=s
+chool></option></tmpl_loop>
</select>
[download]

Perhaps you meant --

<select name="school_id" size="1">
    <option selected value="0">Select school</option>
  <tmpl_loop options>
    <option value="<tmpl_var school_id>"><tmpl_var escape=html school>
+</option>
  </tmpl_loop>
</select>
[download]

Wrt your original question, no matter how you do it, just remember that in H::T each variable is a scalar, while each loop is an array of hash(es). You'll be ok. If you want to not set anything, you can do one of two things -- turn die_on_bad_params off by setting it to 0, or better yet, make sure you set the value to an empty reference. Actually, you can do one more thing -- use tmpl_if to check for existence of a var before trying to display it. Good luck.