Well, I also took my private tree and removed pictures and documents and posted it publicly for DNA. I have trees that are private because of unproven relationships. However, in my opinion, your DNA tree is where you WANT to post possible theories. So if I have an unproven relationship, I attach a caution sign as the profile picture. (see attachment)
I also use various spellings for the last name, for example, if I had an Ann Smith, I spell her father's name Smyth, and grandfather as Smythe, so ancestry will catch the various spellings. If I don't know the parents, I attach unknown Smythe, etc to cover all spelling variations.
I also have some probable surnames in some lines that are used as middle names. If I suspect one of my ancestors may have married a Jackson, I attach his wife as "Ann last name not known", and attach her father as "possible Jackson." This way Ancestry searches for what I consider probable last names, even though I don't yet know the connection for sure.