The survival mode menu appear in creative mode

I can't reproduce this issue. Try /gamemode survival or /gamemode creative.

I don't understand what you mean by "fused together inventories". Are you referring to the XP bar?

I can't reproduce this.

Regarding what Anon Ymus said, if you are refering to the XP bar, it's MC-13592.

The survival inventory is accessible from within creative mode. It's the chest tab in the lower-right corner of the creative inventory.