One sector doing two actions?

To my knowledge, you can't have 2 different sectors with the same sector tag, and have a different action special activate simultaneously for the 2 sectors.

If you're using a source port that supports scripting, you can assign different tag numbers to the 2 different sectors, and have one switch activate (via the script) the pumping action on one sector, and lower the floor of the other sector.

I started writing this and by the time I'd finished @ReX had answered, but I didn't see it until I'd submitted my answer.

Let me make sure I understand the situation. You have a sector that has a linedef trigger set to cause the ceiling to go up and down with a tag of 1. Somewhere else you have another sector that has the sector tag 1. The sector is broken up into 2 parts, one where you intend to have the ceiling raise and lower and the other with the key that you intend to have a floor that lowers revealing the key. That's the mental picture I'm getting from your description.

I don't think this is possible to do with vanilla (I assume this is your preferred format based on your Megawad CP). Unless I am mistaken (which is entirely possible), you set the tag for a linedef and give it a specific linedef action that is triggered on all sectors with that tag. Multiple sectors can have the same tag, so you wouldn't have to have both subsectors defined with the same sector number. So, since you have the sector (regardless of how many subsectors make it up) tagged a certain way, all parts of that sector are going to keep doing the same thing. I don't think there's a way to make the same sector have two actions triggered by a single switch.

I can think of two ways that may work in vanilla to approximate what you're trying to do.

Method 1 (all numbers are examples):

1. Separate Sector 2 into two sectors, Sector 2 and Sector 3. Give Sector 2 (the one that is going to go up and down) Tag 1 and Sector 3 (the one with the key that will lower) Tag 2.
2. Have your switch (with Tag 1) cause the ceiling of Sector 2 to go up and down.
3. Put a walkover line (or lines depending on the exact geometry surrounding the switch, all having Tag 2) very close to the switch, so you will cross it very close to the time that you reach the switch and activate it. Make the walkover line cause Sector 3's floor to lower (or ceiling to raise), revealing the key. It will appear superficially that the two actions happened at the same time, activated by the single switch. Make sure to make the walkover line(s) invisible.

Method 2 (all numbers are examples):

1. Separate Sector 2 into two sectors, Sector 2 and Sector 3. Give Sector 2 (the one that is going to go up and down) Tag 1 and Sector 3 (the one with the key that will lower) Tag 666.
2. Sector 2 will have a floor of height 0 and a ceiling of height 128.
3. Sector 3 will have a floor of height -8 and a ceiling of height 128 (this will create a small recess in the floor).
4. Put the key in a recess in the floor under Sector 3 (a recess is probably unnecessary, but adds to the "realism" or not having the key crushed under a column).
5. Create Sector 4 in the void. Sector 4 will contain a subsector (Sector 5) that will be tagged with Tag 1. Within the subsector, place a Commander Keen. Make Sector 5's floor 0 and ceiling 72 (the height of the Commander Keen).
6. Have your switch (with Tag 1) cause the ceiling of Sector 2 to start a fast crusher.
7. The fast crusher will go up and down in Sector 2 (your pumping sector) and Sector 5 should crush the Keen, causing Sector 3 to raise, revealing the key. They should appear to be nearly simultaneous, thus, two separate actions triggered by 1 switch.

What I did to make it simple was, i just put a linedef i front of the switch, so when you go walk over it, it lowers the floor.  Figured that would be my best shot, and it worked.  But thank you for your replies  Ill keep these ideas in mind for more of my wads