davidlallen
Deity
1. A small bug in that when I create my first settler, I get like 3-5 repeats of the pop-up telling me I've built my first settler.
I have never seen that popup. Is that related to the tutorial or something? Do you also get popups when you play vanilla about your first archer, etc?
2. The religions seem a bit odd. I almost think you need to 'do away' with them and go with more of what you have in Fury Road or what they have in Planetfall of more of 'themes' of how to progress.
Interesting suggestion. There is more background on the religions on this thread in the subforum. Please stop by.
3. My only semi-complaint is that it seems too easy (or at least too early) to get a win w/terraforming.
Are you using the 1.5.5 patch? We have moved the Arrakis Transformation tech much deeper into the tech tree by adding another tech as a prerequisite. However, we have also gotten feedback from others that the terraforming victory is too easy, and it should instead count terrain plots and give a win when 3% of the terrain is transformed. Some more discussion and background at this thread.
4. I haven't played them yet so maybe I've missed this, but shouldn't the Ixians have a 'problem' like the Fremen or Atredies in that when those factions go for Arrakis terraforming there is a repercussion for certain Ixian units being created?
Not sure what you mean. Ixian units are cybernetic; they don't care about terraforming except maybe for rust.

6. Plus, just a thought, have you considered perhaps doing something like what they did in the The History of the Three Kingdoms mod where the Emperor is a unit that is capable of being captured?
I do like the heroes and emperor unit in HOTK. There are a few things we still need to "dunify", like wonders and UU/UB; once everything is done, adding heroes is something we would like to consider.
7. Any plans to possibly allow a way for units to be bought from the Spacer's Guild?
Plans, no. It is already in the game. Please see the "reinforcements" section in the Dune War Concepts tab of the dune-o-pedia. You need a landing stage built, and then you need to find the homeworld screen button at the upper right of your window. (It looks like a greek helmet in the 1.5.x versions.)
8. Is there a problem with the Thumper promotion? I've never found a way to activate that function.
It should act like a lightning rod, to attract worms away from other units and then disperse it harmlessly. But it is not working yet; I need to modify the worm AI.
Though I must say the worms act a bit strange in that having workers out on the sand doesn't seem to attract them as much as I would have thought. Plus (and I'm sure this is a AI thing) I've noticed they often get 'attracted' to units in cities right on the border to sand and take forever to leave.
Hm, those both sound like bugs. I will investigate.