Tell me please,  it is possible to implement these terms in the questing profile using code?

1) change fight class

2) to activate the plugin

3) changing the type of the bot (for example from quester to party)

Hello,

1:

        wManager.wManagerSetting.CurrentSetting.CustomClass = "fdsfsd.xml";
        wManager.Wow.Helpers.CustomClass.DisposeCustomClass();
        Thread.Sleep(1000);
        wManager.Wow.Helpers.CustomClass.LoadCustomClass();

2: 

wManager.Plugin.PluginsManager.DisposeAllPlugins();
foreach (var p in wManager.wManagerSetting.CurrentSetting.PluginsSettings)
{
    if (p.FileName == "myplugin.cs")
    p.Actif = true;
}
wManager.Plugin.PluginsManager.LoadAllPlugins();

(but you can run c# code in your quest profile, it is better way http://wrobot.eu/forums/topic/5272-new-script-node-in-quester-profiles/#comment-24318

3: You cannot