When they fix the quest to give you the pioneer, they also will have fixed the quest maps to give you something other than that one quest over and over - so you won't always get it.

Do henchmen count as Champions as far as the Experience dividing goes ?

No, they don't. 

They need Influence to train, and if you don't have any, the standard designs won't show up.

So I have to custome design a henchman unit for any to show up?

Not necessarily. Having even one point of Influence is enough for the standard designs to appear, and you would still need it to train your custom ones.

For me they showed up as soon as I had the required tech (Heroes, I believe?) and I was able to build one, so I also had enough Influence - think it was 20 or 50 per unit. I did NOT have to custom design them and there were 3 types available to pick from.

50, which is really high unless you have some trait like heroic to give you influence, then it's easy.  Influence is a strange resource.  If you need it, like with henchmen, you better design your faction for ways to get it, or you may never have enough of it to do anything.  There are prestigious places that give it, and a few city improvements, but it doesn't add up to enough to count on to be able to build more than a few henchmen during the course of a game.  But, if you have heroic, which gives 50 every time you complete a quest and you have wanderlust where you can buy quest maps, you can pump out henchmen left and right. (Altar has all that).  Now, if you want to go for a cheaper option, their is guile that doubles influence income, but this seems to only work with the resources and you may not have access to them or you can use the Legacy of Serrane, which  gives influence with caravans, so you have to establish trade with other factions for it to work, and it can give you the edge in influence to push out quite a few henchmen.

Right, as far as I can tell, Influence has 3 special uses, henchmen, Silver tongue, and the City stealing betrayers ability I have never used.  Henchmen I have talked about, and the Silver tongue abily comes with diplomat.  To really get any use out of Silver tongue  you have to have a source of influence income.  One thing that Kraxis does seem to fail at, is they have extra abilities to use influence, without any real way to get it.  they have both the Silver tongue from Karavox being a diplomat and they have the Betrayer faction ability.  Silver tongue can be a fun ability, and useful, but only if you have the influence to use it, which early on, it's pretty doubtful.  I think Diplomat gives you influence to start, but it's actually not enough to actually use the ability.  I don't really have any info on the city stealing spell, I have never used it.

Yea but at shit returns.  I think influence in trade is worth like 2 gold.  And the AI's influence is worth like a 100 each, so if you need it to build Henchmen, or resources like Ogres, you can't trade for it either.