I have seen the last 30 + episodes of DBGT, which is rather cool since I
have a DBGT site too...anyway...

1.  Who are those kid-version Gokou and VEgeta at the end of the last
    episode? Who are their parents? (Pan, Trunks, Bra or someone
    else?)

That was Gokou Jr.  supposedly Pan's grandson.  The DBGT movie special
should explain this better, but I haven't seen it yet.  The little Vegeta is
Trunk's grandson, by inference from Trunk's appearing in a writwatch message
from the Bulma lookalike...the DBGT summaries is rather vague about this one
too.

2.  What happened when Son Gokou (the real one) absorbed the
    dragonballs?  Why did he do it?

Well, as far as I remember, Shenlon's condition to Gokou was that he should
come with him...and Gokou realized he'd be gone a long time so he asked to
say goodbye to all of his friends first.

(My copy was in the original Japanese so I couldn't understand
anything apart from the pictures.  It's still cool though. ^_^)

Hey, me too...