Are These Possible For A French Horn?

Are these passages possible for a solo french horn? The tempo is Andante (quarter note = 90 bpm).

I know brass instruments have some limitations (like any instruments), but I'm not very acquainted with it... =/

(Sorry horn players if this post sounds like understimation, that's not the aim!)

Is this supposed to be transposed or not? If it's regular (in C) then it's impossible on horns.

It's already in standard notation (transposed).

Could you give me a more detailed explanation on why this is impossible? =D

If this is C (non transposed) it's way too high for horns.

When transposed (in F) I dare to believe it's possible although I would consult with a top horn player first. The skilled hornist comfortably plays up to C6 (not to begin a passage with this tone, though) which of course sounds a fifth lower (an F5).

It is transposed here (the original "key" is C major). So, the highest note is an E4 (notated as B4), am I right? So, what's the problem? I still don't get it... =/

It's probably better to avoid such a high beginning of the passage - very difficult to adjust lips to such high note. Perhaps a glissando up to the first note would help a lot to make it easier.

Which note you'd say is safe to start with? (any problem with the second passage? In fact I was worried about the mordents)

The trills on horn sound weird but I believe this is not problematic, only if the fingering would be strange.

The highest note to begin safely is probably g4, maybe a flat, but it's quite possible to miss it.

Thanks! I'll decide what to do...