Question 1 it is possible to send lists or up to two objects depending on the setup of your page into a microflow. If you have a parent view and a datagrid your datagrid action buttons will have the ability to pass the parent view object and the datagrid record(s) selected/searched to the microflow of the button. If you want to pass multiple objects through a wizard for example you will have to create a helper object that has associations to everything you need to have.
Question 2 these variables are available in the microflows/entity access/xpaths almost everywhere so I do not exactly know what you mean by not being able to reach them.
To add to Mitchel's answer.
Depending on the use case a simple setup could be to create a helper object with all the parameters you need as attributes. And send that one helper object to the page where you want to use those.
Thanks for the quick response.
To clarify the Q2 :): On an Activity of Show Page, Show Page->Input->Object to Pass, there is a drop down menu, filled with the objects which I expect to be globally reachable (I expect globally reachable objects not to be in any "object passing" context since they are already global and are not needed to be passed).
currentSession, currentUser, latestHTTPResponse are three of them.
My question is, to refer to Mitchel's point, why are they "everywhere"? They should not be in "object passing" menus since they are already global and should be already reachable.
Or a pre-question, are they not globally reachable?