i wonder what does / dl [player ID] do?

if u mean for example /dl pooman123 it downloads my textures and flames and colors and stuff into your toribash customs folder as my personal folder, then you can type /lp 0 pooman123 to play as me with my colors, flames, and textures

thank you for telling me because yeasterday one guy asked me to do it. i asked him Why but he said that it is very fun / thank you because i could get ban/

You won't get a ban for doing it, toribash does it automatically when you see the person ingame.
You get banned for taking peoples textures out of their custom folder and either, using them yourself or selling them.

Yes, well basically the /lp function (load player) loads up someone's items.
That, if that someone has items in his own custom folder.
/lp basically means the game loads everything from a specific folder where textures and items are "stored".
The load player function has two parameters, the first one being 0 or 1, which means the player's location.
Basically tori and uke are standing in two different places, and that 0 or 1 refers to those places.
0 means the stuff gets loaded onto uke (right rangdoll) and 1 means the stuff gets loaded onto tori (left rangdoll).

The second parameter specifies the folder from where the stuff (items/textures/flames) are loaded, that being a username.

These folders are named as the user, so it's easy to check someone's textures if you have him downloaded (riiight, don't think you're gonna get away with stealing someone's textures).

So basically /lp 0 slipanc will put my stuff on uke, /lp 1 slipanc will put my stuff on tori.