So I am coming back to this with just a few additional comments:
1) I have been watching a number of the lets learn videos by Spink and the scrolling of the map in his videos is much faster and less laggy then on my system, and these videos are years old.
I find it difficult to believe that my system could be less capable that a system that much older, especially with the graphics card I have in mine - but oh well.
2) the slider that is supposed to allow you to change the amount of system RAM the game can use seems to not work in the current version. No matter where I set it, if I then switch to another tab in the settings or close and restart the game it is always in the far left position.
3) I have tried all of the texture positions, and they have little to no impact that I can discern on the map scrolling
4) Enabling or disabling the loading of all textures are start also seems to have no effect on map scrolling - but it certainly slows the initialization of the game.