As it's been ages since I used Voyager, I installed the latest version and inserting smileys was greyed out for me too.
I closed Voyager, started the explorer and copied the 'Images' directory from my TB program directory to my Voyager program directory.
Afterwards I started Voyager again and I could insert smileys.

Therefore:
Yes, it's normal.
You can correct it yourself.
I don't know whether Ritlabs intends to correct this in the install package, because:
a) Voyager is intended to run from something mobile with limited space
b) The smiley function is rather trivial and only functions when mailing from one bat to another

I hope this helps.