Hi,
I would advise some changes to enhance the performance and readability.

Use macros in order to rename the relevant skills and get them named into WED.

Code:
#define Door_ID    skill1
...
#define State      skill98
#define Type       skill99
...

// uses: Door_ID
action actDoor ()
{...

...
// uses: Door_ID
action actTrigger ()
{...


Identify the doors linked to the trigger before the loop and save them into a local array, so when the trigger is activated it only goes through the saved entities instead of the whole level entities.

Code:
#define MC_DOOR_MAX_BY_TRIGGER   4 // whatever
action actTrigger ()
{
   // Set starting values
   ... 
   wait(1); // wait a frame, so all level entities are created.
   ENTITY *entDoors[MC_DOOR_MAX_BY_TRIGGER];
   int iDoorCount = 0;
   ENTITY *ent = ent_next ( NULL );
   for ( ; ent!=NULL; ent=ent_next(ent) )
   {
      if ( ent.Type != TYPE_DOOR )
         continue;
      if ( ent.Door_ID != my.Door_ID )
         continue;
      entDoors[iDoorCount] = ent;
      iDoorCount += 1;
   }
   ...
   int i = 0;
   for ( ; i<iDoorCount; i+=1 )
   {
      if ( entDoors[i].State % 2 == 1 )
      {
         entDoors[i].State += 1;
         entDoors[i].State %= 4;
      }
   }
   ...


Use entity groups in order to scan relevant entities exclusively by ignoring the rest of entities on the scan.

Code:
#define GROUP_DOORS     2
#define GROUP_TRIGGERS  3
...

action actTrigger ()
{
   my.group = GROUP_TRIGGERS;
   ...

action actDoor ()
{
   my.group = GROUP_DOORS;
   ...

action actPlayer ()
{
   ...
   c_ignore ( GROUP_DOORS, ..., 0 );
   c_scan ( ...


Execute the scan only when the enter key is pressed, only once and inside the player action loop.

Code:
action actPlayer ()
{
   ...
   var nKeyEnter = 0;
   while (1)
   {
      ...
      if ( key_enter )
      {
         if ( !nKeyEnter )
         {
            nKeyEnter = 1;
            c_ignore ( GROUP_DOORS, ..., 0 );
            c_scan ( ...
            if ( you )
            {
               if ( you.Type == TYPE_TRIGGER ) // May be different scaneable types of entities...
               {
                  if ( you.State % 2 == 1 )
                  {
                     you.State += 1;
                     you.State %= 4;
                  }
               }
            }
         }
      }
      else if ( nKeyEnter )
      {
         nKeyEnter = 0;
      }
      ...


Anyway I would use the scan event for triggers, so the called event performs all the trigger and doors animations. This way there is no need of a continuous loop for each of them. There shall be a loop for animated ones only.

Salud!