electrical disconnect to water heater (help)
It's up to you, but in this case the inspector is right.
If it were me I would leave the door and add the disconnect. Although in Tx I doubt you are concerned with pipes freezing.
I use $10, 60 amp, "pull out" type disconnects for water heaters. The whole thing costs less than just a 30a two-pole toggle switch.
Sometimes I feel like if I answer any more questions it is like someone trying to climb over a fence to jump off a bridge and me giving them a boost.