Welcome to the forum, we're glad to have you with us!
1) I'm taking my Versys to a shop in Maiden, NC to have my stock seat modified on October 25th. Once they see a complete bike in their shop, they are ready to have other customers send in just the seat for modification. The Corbin seat is an $$$ option as long as you don't plan to run luggage.
2) I have the Givi screen and the (obviously) the stock screen. Right now, I'm running no screen as the buffeting is zero. When the weather gets colder, I envision riding more with the Givi, although the buffeting for me is horrible. Some riders just lover theirs. Try to borrow one and see if you like it before you buy it.
3) Not sure, I always ride with ear plugs to protect my hearing. Calls can wait, one less distraction might save your bacon someday.
"ride more, worry less"
2005 Suzuki GSXR1000 (slightly bent) - Track
2000 Honda VFR800 - Street