There's absolutely no effect on any of those. To address each question separately:
Item Drops: Each item drop has a set rate for each enemy--usually something like 10, or 40. This number is multiplied by your item find rate to calculate the chance of getting that drop. Raise your own find rate by raising Willpower, or equipping the Jester's Hat, the Brightcoral Ring, and/or the Kismet Ring. All these bonuses stack.
Salt Drops: Each enemy has a predefined amount of salt which it will drop. You can multiply it using the Grasping Ring or the bonus from a Leader in the area, and these two will stack with each other but not on top of themselves.
Gold Drops: Again, the only way to modify this amount is through the use of equips such as the Merchant's Fez.
I'm getting this info from my own examination of the game files, which can be unpacked using the Salt and Sanctuary Editor, which you can get here.