About extra fees on train service

For my trip I will be using the Shinkansen and Tokkyu along with other train service, to travel around place with the kansai wide pass, this pass allow me to travel on these trains at a non reserve seats, what about the Limited Express Fee , do I have to pay for this, is this mandatory.

If you are allowed to ride the shinkansen and limited express trains in the non-reserved cars, then there's no additional fee you have to pay when using that pass.

The limited express fee would have to be paid if you decide you want to sit in reserved seats on those trains. The pass would then only cover the base fare.

Thanks for the reply, I just can't find the details about this, the JR site only mentioned that the Japan rail pass covers this, but no specific description, this has been puzzling me whether I should get the wide area pass or not, or should I make other arrange as one area I will be visiting is Amanohashidate, and whether to cancel it for other locations.

Seems like my itinerary is a go, but I still have about 6 Months to consider other options, or if I find other places worth going to, If I was in Tokyo, I wouldn't bother about the pass, I will just get a rental car.

My itinerary is posted here.

https://www.japan-guide.com/forum/quereadisplay.html?0+163095

Thanks again, You have been a great help.

Everything about Kansai Wide Area Pass is here:
http://www.westjr.co.jp/global/en/ticket/pass/kansai_wide/

I've already read it, it doesn't say anything.