So whenever I receive a like for any post, on my profile page it says that it's liked by myself with the avatar of the actual person who "liked" it, but no name. Is that intentional?
it's a vbulletin flaw (or so it would seem) if you hover your mouse over the avatar you get a link to the person who liked your post - depending on your browser, you then get to see the name as a full link in the status bar (wherever it may be in your browser)
no limits on how many as such - there may be a system limit as to how many you can give per minute which will give you an upper limit but you would be hard pressed to give 1440 likes in a 24 hour period (1 a minute) any way......
as for the benefits; think of it as a badge of honour for sharing knowledge or wisdom, or a badge of humour; as those are the two most common reasons you get a like