Regarding bluecountry's question #2, it appears you won’t be able to go from northbound Route 28 to westbound I-66, regardless of whether you want the general-purpose lanes or the HO/T lanes. Similar reason to what froggie cites–you can use Route 29 to connect (basically the same movement he mentions, just in reverse), though I don’t know whether that will offer express lane access because I haven’t looked to try to find out. But southbound Route 28 will connect to the HO/T lanes in both directions, per tracing the ramps in the rendering above, and northbound Route 28 will connect to the eastbound HO/T lanes.