[Avodah] Machnisei Rachamim

[Michael Mirsky]

On Areivim, with regard to a video performance of Machnisei Rachamim 
at Slichot Micha Berger said:

"(Not that I personally say "Machnisei Rachamim". For that matter, I
don't even say "borkhuni leshalom". My current solution is to replace
it with the verse Sepharad says that Ashk skips, "Beshivtikhem
leshalom".)

Is this because of the issue of it appearing that we are davening to angels
as intermediaries (I believe this is a concern of the GRa and others)?

Actually, this bring to mind a halacha that I heard that one davening
in private shouldn't say any parts of the davening that are in
Aramaic because when you daven b'yichidut you are relying on angels
to take up your tefilla.  And angels don't understand Aramaic!  But
when davening in a minyan, the shechina is there directly.  If this
is an authentic halacha, it seems to contradict the view that we
shouldn't be (and can't be) davening to angels in the first
place!  So I ask, is this an actual halacha?  And if so, how do we reconcile
with the angel issue?

Michael Mirsky
Thornhill, Ontario