For auctions - I agree. It would be nice to get a notification, same as we have a notification when a trade expires. Though even with trades, I wish the notification came a day in advance like "trade expires tomorrow" instead of "trade already expired".

For the other things - the game already provides organizational features you can use like tags and tabs. You can have a tag/tab for show horses, retiring horses, foals, whatever else you want. 

Support for auction related pop up/updates. 🐴

I would love a reminder about trades!

I've added the Marwari/ Akhal Teke days to my calendar on my laptop. It works really well - I've set it for around dinner time so I can snag me some horses after work. lol.