This is a great guide for someone who has never tried margin trading. You have emphasized the risks, which are huge comparing to normal trading, with the dreaded margin call being on the top of them. The main benefit is primarily the increased buying potential, as you pointed out.
I would just add one point: you are already taking huge risks by even engaging in margin trading. Minimize the risk by always trading a portion of your entire portfolio. I know some people are striving to get huge gains and get them fast. As a result, they trade their entire account with huge leverages. Better to be safe than sorry. Therefore, decide to trade a portion of your account with smaller leverages, so if you get liquidated, at least the majority of your funds are still there, and you get to have many additional tries/trades.
Margin trading can works wonder for traders who are discipline and know the risks involved so that he can easily manage them. This is definitely not the right way for people who have gambling as the mindset as it can lead to a big disaster. The most important benefit with margin trading is the leverage offered to the user but of course it also entails risks so one should know the right strategies to contain risks while maximizing potential for profits. As what you said, better safe than sorry.