Hi Shaun,
Thank you for your interest in wpdatatables.

Sorry for late response. 

We are located in Serbia and our working time is from 10:00 to 17:00 CET. business days.

First off all data from that assessment/quiz from Gravity forms have to be integers of floats because (most of them that you need to show) when you need to make chart from wpdatatable only one column have to be string type(string, date, datetime, URL...) and all other have to be integers or floats.

Yes you will need to make table first in wpdatatables from that form and then you will be able to make chart.

You can connect those table and chart so when table is filtered it will be filtered and chart as well. Please read more about this in our documentation on this link.

Showing only the latest data in chart from table is something that is not easy to achieve. You will need a column (field in that quizz in GF) that will be a datetime and then you will be able to set sorting by that column to show the latest values and then to set Display length on 1 and like this will be shown last data in table and also in your chart.

You can try our sandbox site: Front-end & Back-end - you can find a fully functional version there to try out all plugin features. Please note that at the moment it is not possible to test tables from gravity forms on our sandbox, but we are working on this and should be available in near future.

Best regards.