Originally Posted by X3msnake

How would the calculations go?
For example if I had a 12v 1A [#1] and a 12v 0.5A [#2] and a 12V 1.6A, in parallel it would make the equivalent of a 12v 3.1A?
Yes.
Would 100Ω resistors do or would it be too much?

For identical output voltages at rated current, no current sharing resistors are necessary.
12v/1A = a 12Ω load, 12v/0.5A = 24 Ω, 12v/1.6A = 7.5Ω.
12||24||7.5 = a 3.9 Ω load. 12v/3.9Ω = 3.1A.
I don't believe open-circuiting this arrangement will harm any transformers.

If the voltages and current ratings are different for each xformer then you need current sharing resistors, on the order of a few ohms each.