InDesign documents doesn't have a global ppi setting.
(I have noticed the PPI: 72 setting in Document Presets. I can't tell you what it means, but it is not something you should worry about - it has no influence on the resolution or quality of your document.)
InDesign is a vector based application. Everything is basically either vector graphics (text and geometrical shapes) or placed raster images.
Vector graphics are inherently without resolution and the placed images have their own separate resolution depending on which physical size you give them in your document. The pixels of each image don't follow the same pixel grid. If images are rotated, their pixels will even be rotated - unlike Photoshop.
You can check out the Effective ppi of each image in the Links panel or you can set up your Info panel to show the effective ppi of a selected image.
When you export a PDF, to reduce file size, you can choose to downsample every image above a certain ppi to a certain ppi, but no images will be upscaled to this ppi.
An exported PDF will often have images in multiple resolutions and can't be said to have a resolution itself.
In your example, you have created a Photoshop document which is 6.13" by 9.25" at 300 ppi and you place it in a 6.13" by 9.25" InDesign document (no ppi!). Then you would expect the image to cover the entire page when the image is scaled to 100%. The effective ppi of the image would be 300.
If the size stays at 6.13" by 9.25" the image would cover the page no matter which resolution you choose in Photoshop, but the effective ppi in InDesign would of course change accordingly.
It seems to bother you that 100% zoom in InDesign differs from 100% zoom in Photoshop, but it's two different things. InDesign tries to show the correct physical size of your document (on my screen I have to zoom to 93% to get the correct size though). Photoshop displays the pixels of the image 1:1 on the monitor.