Natalya ,

If I remember correctly , I could not send/write a letter to a woman with the Gold status , when I was a Standard member.

If the woman is a Standard member , she can send a wink or a letter to a man.
But when the man is a Standard client he cannot read her letter (wink).

And for the stealth issue.Yes , you can put it active or not.
When it is active , the men will not know/see that you have checked their profile.

I have experienced this personally .......

So , what more can you ask for ??