I've been pondering around lately and kept on stumbling over buggy or lacking mods regarding Adventurers and Travelers that give the busy and immersion I desire in the game. So I decided to make my own and now I require assistance on the two main topics. I cant seem to figure out how people make random encounters within the game. I also have problems regarding NPC's travelling at specific time of the day. It seems that the Travel trigger makes them disappear and never reappear. *NPCS are Unique and Respawns*.

If you guys can at least drop advices or suggestions down. It would help me get close to my current goal during summer on making my first mod that evades the CTD I experience over the current mods regarding encounters and travellers.

Travelling is a PATROL-PACKAGE. Check the wiki. You can set up a patrol that covers the whole of skyrim, multiple cities, a single city, a single building or even just a room.

It's a bit time consuming, but does work. It's not random, you designed it, but it should - if complex enough - appear to be random to a player.

Random Encounters - Aren't really random. They happen after a series of conditions is met (like player is in AreaB, has not completed X Quest, is not currently in combat). XMarkers can be used to test for the presense of the player in a certain area and provide locations for the encounter to take place.

Then the relevant NPC is teleported, or whatever, to the relevant spot and ForceGreets the player to initiate the encounter.

There is a random vanilla encounter where a group of "revellers" hail the player and give him a bottle of mead ... I can't remember what the associated quest is called, though ... If you can find it that will show you one way of making an encounter appear random. Our old friend Maiq also works in much the same way ... check him out too)

As h4vent says, you are the one who sets up the conditions for the encounters. You can also include http://www.creationkit.com/GetRandomPercent as one of the function conditions to give some randomness to the encounters:

Condition Function: GetRandomPercent
Comparison: >
Value: 50

So even when your other conditions are true, this would still limit the "random" chance to 50% (or change the Value to suit your needs.)

There are functions such as http://www.creationkit.com/RandomInt_-_Utility if you need it in Papyrus code.