The particular edits you object to are, in fact, correct. Throughout StackExchange the accepted culture is that questions do not start with a greeting (Hello, Hi, etc) nor do they end with Thanks or any kind of signature. Other "meta information" such as how long you have been working on this, or that you tried searching already are also generally considered superfluous and removed.
Expanding abbreviations is generally not a good enough reason to edit a post on its own; however if I am already editing a post to tackle spelling, grammar and capitalization errors I will also expand some abbreviations while I'm there.
You shouldn't do anything about appropriate edits, but if someone makes an inappropriate edit that changes your meaning, you can roll back to an earlier version. To do this, click on the link that appears after the word
edited under the question, to see a list of edits. There is a rollback link next to each one that you can use to undo the changes. Don't make a fresh hand-edit to go back to how it was.
Also, if you find yourself in an "edit war" where you make a change and someone makes the opposite change, and that goes on for a while, flag for a moderator to help you.