re: Since there isn’t a place to upload an image with those dimensions, from which image (med, large, etc.) does it pull from and can/should I change those image dimension settings to 100px x 130px or will it mess something else up?
No, nothing will get messed up. The is one change you could make, I’ll elaborate in the following answers.
re: Which images do the contact detail page use?
It will use the medium image size.
re: what I would like to do is have images sent to me in the exact dimensions they need to be uploaded – without any cropping or disproportional resizing needing to be done by the system at all. Is that possible?
Any multiple of 100×130 would be fine. For example:
You could choose a large size for your users to send in. Then set the medium image size to a size smaller than you are asking the user for and then let Tile Plus auto create the smallest size. As long all are sizes are a multiple of 100×130 it should be fine.
Does that help?