we have a JR pass during our Kyoto stay, which we want to utilise fully! - makes sense? Yes.
Does "JR pass" here refer to a (nationwide) Japan Rail Pass, or a JR-West Kansai WIDE Area Pass?
Is Kinosaki nice? I did feel Kinosaki nice when I visited it last time, though I did not stay overnight there.
Kinosaki hot spring town has been known well for external baths (called as soto-yu in Japanese), which are outside accommodations.
A one-day pass for the seven Kinosaki external baths is sold at 1200 yen, available at entrance of each of the baths.
(Please pay attention to closed days.)
http://www.kinosaki-spa.gr.jp/global/hotspring/hotspring.htmlAccording to the Japanese-language edition,
Satono-yu is now open from 7 am to 11 pm
and Jizou-yu is now open from 3 pm to 11 pm.
Strolling for one day (and staying overnight) sounds enough just to experience Japanese hot springs in Kinosaki; if you hope to explore the onsen town, it may be better to add half a day.
In Kyoto Station of JR, Limited Express Kinosaki trains use Track 31; the platform for Tracks 30 to 34 and the platform for Track 0 are adjoining around the north end, near the Central Gate.
A JR-West Kansai WIDE Area Pass, when you have a Kinosaki train ride with your seats reserved, does not cover the limited express surcharge, while it can cover the basic fare; when you have a ride without seat reservation, it can cover also the surcharge.
In any of the two cases, a Japan Rail Pass can cover both the basic fare the surcharge.
http://www.japan-guide.com/e/e3526.html?aFROM=2158_3525Is 2 full days sufficient for Kyoto? That depends on sites to visit, your preferences and your traveling pace.
http://www.japan-guide.com/e/e2158.htmlA Japan Rail Pass can be used to take buses on the Takao-Keihoku Line of West JR Bus in Kyoto City, along which there are Ryoanji (Temple), Ninnaji (Temple), the Takao area, etc.
A Kyoto City Bus & Kyoto Bus One-day Pass (sold at 500 yen), which is valid inside the 230-yen flat-fare zone, is useful to access many sightseeing spots including Togetsukyo Bridge in the Arashiyama area, Golden Pavilion [Kinkaku], Silver Pavilion [Ginkaku], Kiyomizudera (Temple), etc.