In certain text editors, like E, I can select multiple locations and, as I type, all the selected locations get replaced with the characters I am typing.
For example if I have:
<tag1 class=""></tag1>
<tag2><tag3 class=""></tag3></tag2>
In E I could select two locations inside sets of quotations marks then start typing and both locations would be updated simulataneously. In Vim, I can select several connected columns at once and then edit them, but I’m wondering if there is any way to select multiple locations that aren’t lined up.
Have a look at SnippetsEmu. It should be doing something very similar to what you need.
It emulates TextMates snippets. You should be able to have one snippet with the same tag repeated, and editing will do the right thing, updating the same tag in all locations, as you type.