Question

I know that I can remove blocks by commands, but is one thing more correct, than the other?
Also, would I somehow be able to remove a .div class instead of a block? so that I can remove a .div from a specific page?

Heres the examples of the snippets I know of, to remove blocks.

<remove name="name_name"></remove>
<action method="unsetChild"><name>name.name</name></action>

Answer 1

Remove – remove block from any level, example block AAA is child of the block left that is child of the block content then I can remove it at top level of page layout:

<xxx_index_index>
  <remove name="AAA" />
  ....

unsetChild we can use only within parent of the target block, example if I have this layout:

<default>
  <reference name="content">
    <block name="BBB" ... />

Then I can remove BBB with method unsetChild

<yyy_index_index>
  <reference name="content">
    <action method="unsetChild"><name>BBB</name></action>