ATCO here.
World TA: Good idea, I guess. (I'm fairly parochial down here). Had no idea the UK system was so complex.
Datalink/Displays/HDG/Altitude: Already under development, I believe. Could be appropriate for some area/oceanic applications, but in the tower the mix of having to type, accurately, ie zero mistakes, combined with the necessity of also using r/t and scanning outside would make it too cumbersome and ,I believe, detract from safety.Touchscreens? We DREAM of touchscreens.
Metrification: Forget it.Unless you want to change the vertical seperation standard to 1000M. Which would ameliorate significantly the effect of level busts, but triple (and then some) airline delays. By metricating the units used, you force those that have to use them into non-decimal think.It's natural to add/subtract a thousand feet, but to have to do that in groups of three hundred? Nope. Speeds in M/s? forces those that use them into thinking in very, very large numbers. (How many metres to the next waypoint/destination; how many seconds fuel remaining etc) It could be argued that this would only be a problem during the transition; I think not. For flights lasting several hours, it makes sense to use units of time and distance that are manageable/meaningful to the brain without having to go into logarithms. And the present ones work well.