Hello,
I often am looking for something that I know the name but I need to scroll all the way to find it.
From the look of the various controls, I'm pretty confident you are using DevExpress XtraGrid in the application. If that is the case, all those things and many options in context menus are built-in without any work. It just have to be enabled (aka AutoFilterRow).
For comboboxes, I think they also support a search "Begin with". This would also be valuable instead of scrolling into a tiny dropdown through all the Project variables. Also, I think someone already asked that they should be sorted. That would also help.
Thank you.