It seems natural to want to express as much good will as possible. However, the online medium resembles a conversation more than a letter. This not only preserves the value of the phrase but it adds sincerity to your post, regardless of whether you use them. Follow Guidelines Within Your Spiritual Tradition Dharma is like medicine, and just because you've been taught a few cures, it doesn't make you a doctor. Check with your spiritual teacher before you take it on yourself to teach or discuss issues of practice and doctrine.
Most teachers make it very clear who can teach and exactly what that includes.
If you are not careful, you could not only harm others with teachings they are not prepared for, but you may also harm yourself by not being equipped to deal with the results. Emptiness is a prime example of good medicine becoming poison when an incorrect diagnosis is made. Many practitioners on the Internet, especially Zen students, talk incessantly about emptiness, or shunyata. This creates a constant crisis among new practitioners, uninitiated practitioners and non-practitioners alike, who have a difficult time grasping this Ph.D. level bit of Buddhadharma. Again, this is another one of those guidelines that you wouldn't think much about in a real-life encounter but for some reason seems to fall away in impersonal Internet meetings.