Those two icons mean that you are setup to receive e-mail notifications and flag notifications (in the forums) for that post. You can toggle that setting by clicking on either one of the images. The x will then disappear.
As of now, there is no way to do a category specific search. I believe some users have developed a workaround. Hopefully one of them will answer this thread
How do I subscribe to a thread without contributing adding a post?
Just click on the email notification button when it has no X. You can't flag a post you haven't responded to, although it will get an automatic red flag to show that you've read it. Instead of flagging it you can add it as a "favourite" or "bookmark" (the heart button) and it will show when you click on the "Show my favourite topics" button on the forum home page.
The third post in this thread by JackNaylorPE is some type of spam!
What? Paranoia can be becoming, but not in you're case.
------------------------------"To better understand why you need a personal computer, let's take a look at the pathetic mess you call your life."
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