As i understand, you have to display messages to the user but i should not stop user to proceed.
How about using Visible when conditions for your messages ? Will that help instead of using validate rules (which will actually add error message to your pages). If there are more number of properties in the form, probably you can display all the messages in one subsection (near to submit button/top of the case where messages will be visible to user).
I agree with Sundeep. You can place warning messages in layout/section with possible visible when conditions in top your section and onchange of every feild apply refresh section.So user will know as soon as they enter data. In this no customizations required you just need to place visible conditions. You can also verify 7.2 CLM had option like on submission of approve button in perform harness they will show confirmation popup. You can try that option as well.