"The father of my mother feels (passively) that that my left ringfinger touches him 2 centimeters in inferior direction from his right earlobe" (At the present he lies on his back, so inferior is not the direction towards the center of the earth).

tê ömmilek audyal íčawëla tê adlaisakenniňk qe oeksrâ’as oimřalik akpʰialîk êntô’alakuňk

There you go. :) It's a very literal translation but it's overly redundant. A hypothetical native speaker would probably drop the "audyal" verb, deframe "íčawëla", and rely more on Ithkuil's extensive case system.

Incidentally, "Dear readers" is "atpëkein".

In English I can say: "Dear readers," without specifying gender.

"The father of my mother feels (passively) that that my left ringfinger touches him 2 centimeters in inferior direction from his right earlobe" (At the present he lies on his back, so inferior is not the direction towards the center of the earth). How would you say that in ithkuil?

I think one of us has misunderstood ithkuil (it may be me). I've only done a bit of looking into it, but my understanding is that it can do both of what you mentioned above. The difference is that you can't say "dear readers" of a non-specific gender without specificying that you mean a non-specific gender. Which means you only say "dear readers of a non-specific gender" if you know that's who you're addressing, if you're addressing only male readers it would be a completely different sentence. In other words, you can be general but you can't be ambiguous. If you're trying to get clearer in your thinking, this is a property you want.

Ithkuil also has all sorts of conujugations that get very specific with object placement and relation to one another. It's almost ideally suited for your second sentence.