maja'chuqjaj?
Can we talk?

isn't here an interrogative {-'a'} missing ? and hold on a minute !
how can we place the {-'a'} which is a type 9 verb suffix, on a word
which already has a type 9 verb suffix ? hmm ?

so, if we apply the rules strictly, we can't use {-jaj} in order to
create yes/no questions..

Don't confuse the colloquial English translation with a word-for-word translation. The Terran says maja'chuqjaj let's talk. Can we talk? is merely a colloquial translation.

lenglIj lutebjaj lengwIjvaD bel rap, Sov rap, ngoQ rap je
Danobpu'bogh
May your journey be filled with the same joy, wisdom, and
purpose you have given mine. (Frasier)

there is something I don't like with the placement of the {lengwIjvaD}
; perhaps it has to do, with me being used to seeing the {-vaD} at the
beginning.

The lengwIjvaD is associated with the verb Danobpu'bogh. Which you have given for my journey.

-- 
SuStel
http://trimboli.name