push/fold at 15-20 big blinds is overkill IMO.
even when i'm legit short-stacked (like 8-10 big blinds), i like to mix in
stop-and-gos rather than just open shoves.
I don't mind having a small range for jamming here. More so around 15BB but sometimes it just makes sense especially in a late position.
In regards to starting stacks. Personally for all tournaments I wouldn't mind having a starting stack around 7500 - 10000. With a short late reg like 30 minutes. Most of the people playing seem to be able to make it work so keeping this shorter for reg/rebuys if available still keep the overall length down. You could go with say an 8 minute level and see how it goes. Just my thoughts on the overall matter. For a championship game I think the more chips the better. Makes for a more interesting game, playing real deep and lets people really mix in some plays.
Also personally I wouldn't seeing a few non-series tournaments. I'm not liekly going to be able to play in many series tournaments moving forward so just having a one off weekly or a longer series season would be something I'd like to see.