You can clear your inventory as a spectator

[WesJD]

I accidentally shift clicked the X in my creative inventory as a spectator and it removed all of my items.

[Pugzy]

Hmm this is an interesting one, on one hand making the items non-removable and replacing them when they are modified would be good for new players however the ability to change your inventory around and remove items is useful in other situations such as the macros mod or whilst spectating.

I hate to say it but.. maybe a toggle, one for a non and one for a sticky (default) inventory.