Are you asking about creating a "Win Game" condition, or for changing the text of the Objective?
"Win Game" is an Action, and is categorized under "Game" when making an action. Anything can be used to trigger it.
For modifying the text, that's more complicated. You'll need the DK2 STR tool located here https://lubiki.keeperklan.com/html/dk2_tools_other.php
I'm not sure if you're making new MPD maps, or overwriting the existing ones, but inside of Dungeon Keeper 2/Data/Text/Default, that's where the STR files are, which have the Text.
Place the DK2 STR Tool's files in there, and you can edit strtool.cmd with notepad or any text editor, and write "strtool 1 2" where 1 is the name of the text file you're editing (it doesn't need the file extension) and 2 is the operation that the tool will do when you run it, which will be "x" or "c". "x" will export the entries from the str file into a text file that can be easily edited. Then "c" will allow you to create a str file from the text file, which the game will be able to use. After setting the operation and saving it, run the strtool.cmd and it'll do whatever you told it to do.
So for example, you'll have "strtool LEVELMPD1_BRIEFING x" which will export the contents into a text file, and then ""strtool LEVELMPD1_BRIEFING c" will put that back into a str file.
And the Briefing str files are what you're looking for. That has the name of the level that's displayed in the menu and the objectives.
I don't know if you can create a new MPD level like MPD8 for example and have the game find it in the MPD menu or if it even would properly find the text associated with it, I never experimented with MPD levels or new text files to that extent, only editing the original campaign files.
Naturally backup your files before messing with them.
And keep in mind that if anyone is to try to play your map, they also would need your text files and overwrite their own text files, which they may be less willing to do as that gets to be kind of a hassle unfortunately.
Researching Rooms and Traps I'm a bit less familiar with, but in terms of making them "Researchable" that's in Keeper Properties. There's a Checkbox next to various items like Spells and Rooms, and 3 settings for it, where a Gray check is Researchable. Click it to make it cycle through those settings.
Creatures should research them automatically, but I recall some issues myself where they wouldn't research Traps / Doors, or maybe that was only if Rooms / Spells were also set to be researchable. Unfortunately I am less familiar with this so that's about all I know.
Without looking at the map, I wouldn't be able to tell for sure. I can only assume you made a Creature Action or something to spawn a unit and it was of Heroic Allegiance. That would spawn a unit without necessarily putting it under Good Player in the level script, as it's instead underneath whatever Trigger is activating it.
Removed.