Hi Mark- This is a good place for your comments and suggestions, and thanks for sharing them. :-)
#1- We have not planned to solve this specifically but I think we will satisfy what you are looking for in a 2015 release. We are still in the planning/design stage but we have a vision to add multiple trend cursors to trends in PI Coresight. As new trend cursors are added the value for each trace on the trend will be displayed next to the cursor. This would include the min/max/avg values if they are currently shown on a trend and therefore would give you the numeric value you are looking for.
#2- I see your point. Should we have two time columns? One for min time and one for max time? Also in a 2015 release we will support the work currently being developed in the PI Server to support future data. As part of this support in PI Coresight we plan to add a "reference time" cursor to the time bar. With this time bar cursor the user will be able to control what reference time is used to show values in tables, value symbols, and gauges on the display. The current time column seems like it will have more value at that point because it will no longer always be the end time of the display.
I hope this is helpful. This all falls into the category of future work that is still subject to change, but it is what we are planning right now. What do you think?