I am glad to hear you like Ez Grab. To preserve your changes through HPDB updates, you just have to check the box labeled "Preserve Changes" (or something to that effect) in the system setup box and then save the DB. When the HP database update is complete, the new systems will still be there. But you will need to use PP to upload to the HP1 as Sentinel might not pick up on these custom systems.
For the fill down, you can do this presently by holding down Ctrl and choosing all the channels you want to make a change to. Keep holding down Ctrl while making your chance, then click on another channel and the change will apply to all the channels you selected.
I'm going to look into the bugs with the tags. I know the "other" tag is not used in the HP1 which is something I found out after release. So its something for the next version to address.