I'm a huge fan of Yu-Gi-Oh GX ^^ I've seen all the Japanese episodes so far and I must say it's an amazing series, the characters are very intresting and the humor in it is pure hillarious, I can be in stitches laughing through a whole episode soemtimes cos it can get quite crazy at times, it has it's seriousness later on in the series though if you prefer seriousness over humor ^^
I warn you not to be put off by the apparent lack of a plot early in the series, trust me, there IS a plot there but they start off building it very slowly underneath the random episodes that let you get to know the characters and their decks and such. Later on in the series you'll soon realize how even very early events in the series have an effect on the later storyline ;D
And as for Yugi giving away Winged Kuriboh to Juudai in the Japanese version he simply stated that the card wanted to be with him, in other words Winged Kuriboh wanted to be with Juudai, simple as that really ^^ As for not showing his face, that might have been because they were focusing more on Juudai as a main character than Yugi. They don't want to overshadow the new characters with the old ones I imagine.