I think you're right-- tolls are going to happen in NWA. If all goes according to plan, I think Bella Vista might be the first toll in Ark. The Bella Vista bypass toll study is being updated as we speak and should be completed this spring; the final design is being done as well. I think ROW/utility work is about to begin.
I-540 is pretty congested, but still isn't nearly as bad as big city freeways. However, after more interchanges get improved, as the area grows, and as more developements along I-540 attract more people, it will get worse. The main problems now are really at the interchanges. Unless money falls out of the sky, what will likely happen is that pieces of I-540 will get widened to 6 lns (instead of all at once) along with major interchange improvements until it is 6 lns, then later 8 lns. Fortunately for NWA, almost all of the necessary ROW for main lane widening is already there, so the cost to widen 540 is relatively inexpensive (compared to big city freeway widening projects).
Agreed on your third point. NWA planners are working on this problem right now... in fact I was in a working group meeting yesterday working on this very issue for NWA. We all really, and I mean really, recognize this particular issue needs to be addressed now. The difficult part is working with all these seperate jurisdictions... all with their own wants, needs, and agendas. Fortunately, they have been generally receptive and agreeable (I'm not involved in that entire process), so as long as people/politicians/AHTD/etc. keep pushing the issue (i.e., the need for better arterial and network connectivity), the local MPO and the local jurisdictions will come to agreements I think for some of these major arterial corridors hopefully. I think that falls into the category of 'good planning', which requires lots of time and effort, and fortunately the MPO up here recognizes that is working on it now.