Now that I think about it, your concerns about the multipliers are actually valid. While I wouldn't look at it like it screws up scaling of scales (it does not, with scales, you simply crank up even more troops from a single fort), what it does in general is speed up the game, especially the early phase. It does have few other noob-friendly quirks about it, for example if you screw up your initial expansion and get owned by independents it's easier and quicker to boot yourself back up.
But as I think about it now, it can have unpleasant effects too. What actually came to my mind and is a good example, are nations that have capitol-only good researchers. A nation than has recruit-anywhere option gets significantly bigger advantage from these multipliers than a nation relying only on it's capitol... This "issue" is of course always there, but a resource/gold multiplier easily makes the gap bigger and out of bounds.
And a very valid point is that usually, multipliers are left on default for most games and that's something we are/need to be accustomed to.
So, changing all multipliers to default values is sensible. If no one has any objections, let's set them on default.
Regarding the magic sites mentioned, to be honest, I copy pasted the settings from our previous game but color me blind, I don't see magic site multiplier changed. I don't recall changing that in the previous game ever, this is supposed to be default.
Also, let me welcome more new players! My current plan is keeping this game open to join 'till Friday or until we reach, say, 18 players, which ever comes first. I enjoy long games with plenty of space to expand, but there are extremes on both sides and a game with 400+ land provinces would be simply insane