There is no private message feature on the forum. If you agree to keep information private, you should do so and you shouldnt try to strong arm the disclosure of private information, nor to strong arm someone into vouching for private information.
I dont think a reasonable person would believe it is not safe to trade with techshare. To my knowledge he doesnt have any trade complaints, he is not taking steps to have larger amounts of other peoples money at once and appears to take steps to be transparent about terms of his trades. Most of his negative ratings are about personal disputes in which nothing of value is involved. I dont particularly like Suchmoon, and I find it hilarious to see her on her heels when not supporting the most powerful side in a dispute after year of her brownosing any and everyone in power who are involved in a dispute, but she is right about the rating (not about the forcing private information to be public). Techshare may have viewpoints or opinions that others might view are bad but they do not nearly reach the level that makes him dangerous to trade with.