I have both an RB433AH and an RB750G.

I have concluded that on the RB433AH, it is not possible to remove Ether2 and Ether3 from Switch 1.

I have concluded that on the RB750G, it is not possible to remove Ether2, Ether3, Ether4 and Ether5 from Switch 1.

Are these appropriate conclusions ?

F.

It is possible to remove ports from switch by setting master interface to none.

Flags: X - disabled, R - running, S - slave
# NAME MTU MAC-ADDRESS ARP MASTER-PORT SWITCH
0 R ether1 1500 00:0C:42:21:78:40 enabled
1 R ether2 1500 00:0C:42:21:78:41 enabled none switch1
2 R ether3 1500 00:0C:42:21:78:42 enabled none switch1

As you can see, port 0 is associated without a switch

Port 1 and Port 2 have master-port as NONE but are tied to switch1.

F.

SWITCH group indicates only that ethernet is controlled by the same switch chip. It doesn't mean that ports are actually switched together. master-port parameter does the switching configuration.

Does that mean that Port 0 is not on the IC plus switch chip on the 433AH ?

Yes, only ether2 ether3 are controlled by switch chip.