Hi Pragmatist, welcome !
I am not sure what your problem is about, you have got a good party so far, there are other NPCs but you should not have any problem meeting them in a quest or another. Did you try all the secondary quests ? What character are you playing ? I don't want to spoil anything for you at that point, that's why I am keeping on general ground here. You should go on with the game as you have started and not worry, so far you don't seem to have missed anything crucial. What is it that you need us to tell you without soinling you of the joy of discovery ?
Oh, if you are talking about Jan, he is said to be the funniest NPC in the game. I got him late in the game, but I don't regret having taken him, he made me laugh to tears more than once !
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The world is my oyster !
And now I have the knives to open it ...