JR pass or separate pass

I will be travel to Osaka Nov 10 so from Nov 10 till Nov 17 , I'll stay in Osaka, but I'll visit Universal , Kyoto, Nara, Okayama or Hiroshima, Tottori

And from 18 till 23, I'll travel to Fukuoka and stay there and visit oita and beppu, then back to Hiroshima and Nagoya and the last day travel to Tokyo

so I was thinking to take jr pass for 14 days is better or shall I take separate pass like one Kansai Hiroshima regional pass with jr pass or sanyo pass etc .

is it better and low cost to take separate tickets or should I stick with 14 days ?

and is it allowed me in the first place to take different JR pass as a tourist