Help translate these two sentences with 也未必 and 更何况
有时就连你的父亲也未必信得过，更何况是陌生人。


Sometimes you can't even trust your father, not to mention a stranger.


  有时连陌生人你也可以相信，更何况是你的父亲。


Sometimes you can even trust a stranger, not to mention your father.

I think even...not to mention would be a proper translation for 连...更何况, 也未必 is just a word indicate that the sentence is negative.