Icoca

zalmi

I'm traveling to kansai for 7 days, staying in osaka for 4 days and kyoto for another 3 days, I heard about icoca kansai one pass and wondered if this covers my journey via JR and also private rail ways, and in any other exchange stations. Or should I just buy the usual JR WEST rail pass?

Tenjin

You need to clarify things a bit more - JR West has several passes, and it's not clear which one you mean. If you mean the Kansai Area Pass, it would not pay off without some long distance travel, such as going from Osaka to Himeji for a day trip.
For your other pass, perhaps you mean an ICOCA+Haruka pass? This could save you some money. It may help you if you look at the various passes for JR West on
https://www.westjr.co.jp/global/en/ticket/
Another useful pass might be the Hankyu tourist pass
http://www.kansai360.net/en/ticket/
Also, if you are visiting Kansai, you should not miss Nara either - it has some of Japan's top sights.