Everything you say is correct but it would be good to see him use his physicality.Even though he has that as an asset he tends not to use it so in my opinion he is not unique ( he could be if he used his power and added workrate to his undoubted talent) and is far from irreplaceable.
A contract at the reported figure of £100k per week is generous imo.
As a self confessed signed up member of the Ross Barkley fan club you won't be surprised to learn that I heartily disagree with you on both counts.
Ross does use his physicality and his power. He is excellent at retaining possession of the ball and is rarely outmuscled. How many other midfielders in the premier can you name that make those powerful surges from deep setting up most of our counter attacks. There are some but not many. And his work rate has improved tremendously under Koeman.
As regards wages, I would say between £100k and £120k is fair if Rom has been offered £140k. He could expect that and more if he went to the likes of City, United or Chelsea. If you want us to compete with these clubs we have to go some way towards matching the sort of salaries they pay. That applies to new signings too if we are to attract them here, so when Joe Bloggs comes in on £100k pw how is Ross going to feel on £80k pw when he carries the burden of being our main creator?
I said in my post that he isn't irreplaceable and I believe that. But I'd still much rather have him playing for us than against us.