Do I have to "quote" others whenever I want to make a specific comment about something someone else has said?
Short answer is, No. Longer answer is still "No, but". No because threads are a stream of conversation, just as though we were all sitting in a room together. If you are responding to the post immediately before yours, no, you don't have to quote as it will be obvious what you are responding to. If there have been a number of posts all related to the same post, then no again, you are just adding to the current discussion. If however, you are wanting to ask a question from a bit further back or a specific point that is not currently be discussed, then by all means use the quote link. Keep in mind that you don't have to keep all the text in the quote. If a quote is 10 sentences long, but you are interested in only one sentence, then quote it and delete the extra.
Keep in mind that folks are reading your post - extra text or quotes just means more "junk" they need to read through before getting to the important stuff. If you need it, quote, if you don't, be kind to your readers and don't.
