vargatom

This is not a goal. It's a paththrough navigation. It is executed when a bot goes through that waypoint. Bots visit that location because there is DEFEND goal. If you want to change priority or make it class specific, you can set it on the DEFEND goal.

Why don't you use the PrintScreen key or Snipping tool to make screenshots ?
There must not be "=" in server.cfg. You have to delete = after set omnibot_path.

Where can we download pk3 file of this map ?
You should never use entity numbers because they depend on mods. You should use GetEntityByName instead of GetGameEntityFromId. If the entity does not have any name, then you can use TraceLine.
Functions GetEntityByName and GetGameEntityFromId return null if the entity is invalid. Correct condition is:
if(ent1) { print("Entity is valid"); }  
You must not use GetEntTeam in OnExit because it returns null if a player disconnected. Players can also change team when they are inside the region. See wiki how to count players in a region.

You cannot query the current stamina.

This is not related to bots. The same problem happens if you watch human players. There are a lot of bugs in the omnibot mod because it is based on the original game from year 2001. The spectator stamina is displayed correctly in newer mods (legacy, nitmod, noquarter, silent). It does not work in jaymod and etpub.

gm scripts are case-sensitive. There must be Goto, not GoTo.
Why didn't you copy the function from this page and paste it into your script (Ctrl+C, Ctrl+V) ?
 

The end of EvalFunc }, should be on line 79 after return, not on line 86.

Navigation = { stop = { EvalFunc = function() { return !this.StopTime || GetTime()-this.StopTime > 2; }, navigate = function() { this.Goto(this.Bot.GetPosition()); sleep(3); this.StopTime = GetTime(); }, }, },  

Use Paththrough Navigation
Navigation = { stop = { navigate = function() { this.Goto(this.Bot.GetPosition()); sleep(3); }, }, },  
/bot waypoint_setproperty paththrough Navigation_PT:stop

After the wp_check command you can use commands /bot wt DUPE1; /bot wt DUPE2 etc.

You can set g_engineerChargeTime

Updated.
 
server_api.zip

The chosen botToKill is never an engineer because botToKill has goal FLAG, but engineer has goal PLANT.

foreach(g in Util.GoalTable("FLAGRETURN.*")) { Util.MapDebugPrint("Position " + g.GetPosition()); }  

It does not count dead players because dead players cannot carry anything. But you can get distance to a dropped object from a FLAGRETURN goal.
foreach(g in Util.GoalTable("FLAGRETURN.*")) { d = DistanceBetween(g, Vec3(-1824, 2115, 4)); Util.MapDebugPrint("Distance " + d); }  

for ( i = 0; i < 64; i += 1 ) { if ( EntityIsValid(i) && GetEntFlags(i, ENTFLAG.CARRYINGGOAL) ){ d = DistanceBetween(i, Vector3(-1824, 2115, 4)); Util.MapDebugPrint("Distance " + d); } }