Haruka and ICOCA pass

Hi. I would like to get some more information on the Huruka and ICOCA card pass.

I see this a great deal for traveling within the Kansai region. It seems to be more convenient for the traveling process. I would like to be really sure this is good for me.

I will travel from Kansai Airport but need to get off at Osaka Station. I will becoming in late to Osaka so having to walk further is not preferable from the shin-osaka station. I feel I do not want to waist money on the Haruka if I am not to actually use it. I will take the JR Kansai Airport Line instead. Any thoughts on this being a big waist of money if purchased?

I will also travel Kobe, Kyoto, and Nara. All in 4 full days.

Will I need to purchase a different ticket to Nara?

I will have to take limousine bus to the airport because of an early flight, can I use the ICOCA card?

If I am to purchase this Huruka and ICOCA card, is it best to get a one way or two way card? I am confused a little, if I get a one way does it mean I will not be able to use the card after the first day ANYWHERE or is this just for the Huruka rail?

Last question. If I go to Kyoto, can I use the Huruka line from shin-osaka or is it best to just take the JR Tokiado/Sanyo Main line?