I actually have the Apple Keyboard as well, which is somewhat better since it does have an Escape key, but the other problems still apply unfortunately.
I have the Office suite as well (and the iOS apps seem excellent), but unfortunately we have some stuff in Sheets that relies on scripts that run there, and can't be used in Excel. Not sure if Google is deliberately dragging its feet on iOS or what, but it's not good enough for professional use right now, and mobile Safari is also not there yet.
So a request...send google some feedback on their apps.
As to excel, I think you would have to look into a surface pro, if you want a tablet, but still have script functionality.