When you say that these field objects on your layout have different names, what are you looking at? If you are looking at text on your layout, you can label a field with any text that you want and thus the same field object can be duplicated and given different label text. But this would then be the same field and you'd see the same data in both field objects. I don't know for sure this is the case but it would fit what you describe. Check your field objects by clicking them while in layout mode and check to see what appears in "display data from" on the inspector's data tab. If the same TableOccurrenceName::fieldName appears in both cases, you have duplicated the same field on your layout and this is why you see the same data in both.
Other ways that one field can have the same data as another:
A script trigger in Field1 can perform a script that copies the data from field 1 to field 2 each time that the data is modified in field 1.
An auto-enter calculation in field 2 can copy the contents of field 1.
Field 2 can be a field of type calculation and thus copy the value.
As for your last question, select the field while in layout mode and use the data formatting options at the bottom of the inspector's data tab to specify a currency format for it.