Are all the *coin networks consistent in which script actions are permitted and disabled?
Short version
Yes.
Long version
Bitcoin
The bitcoin implementation of banned opcodes is in script.cpp:
        if (opcode == OP_CAT ||
            opcode == OP_SUBSTR ||
            opcode == OP_LEFT ||
            opcode == OP_RIGHT ||
            opcode == OP_INVERT ||
            opcode == OP_AND ||
            opcode == OP_OR ||
            opcode == OP_XOR ||
            opcode == OP_2MUL ||
            opcode == OP_2DIV ||
            opcode == OP_MUL ||
            opcode == OP_DIV ||
            opcode == OP_MOD ||
            opcode == OP_LSHIFT ||
            opcode == OP_RSHIFT)
            return false;

Note that this is not a complete list - OP_NOTEQUAL is also disabled. This code struck me oddly because it appears to create a fork with transactions that use OP_NOTEQUAL. (Perhaps it wasn't being used.)
                // OP_NOTEQUAL is disabled because it would be too easy to say
                // something like n != 1 and have some wiseguy pass in 1 with extra
                // zero bytes after it (numerically, 0x01 == 0x0001 == 0x000001)
                //if (opcode == OP_NOTEQUAL)
                //    fEqual = !fEqual;

Source.
Namecoin
Same.
LiteCoin
Same.
SolidCoin
You didn't ask about it, but it's also the same.