entry is available without query when templates are set in the CP, is this an acceptable method?
the simple answer is: yes it is an acceptable method!

In single sections or in a single entry of a structure or channel, this is totally fine. 

You need the entries query if you want to do something like having a list of all recent blog posts on your homepage. So on your index.twig the "entry" object has got all data for the homepage, like title, url and all fields! 

Example index.twig:

&lt;h1&gt;{{entry.title}}&lt;/h1&gt; &lt;---(the title of your site)

{% set blogPosts = craft.entries().section('blog') %}
{% for entry in blogPosts.all() %}
  {{ entry.title }} &lt;---- (the title of a blogpost)
{% endfor %}