I would like to make KDE startup faster; I noticed that there are many applications that run on boot, that maybe I don't really need. Where could I go and change that? (safely)
You can try to go to "System Settings" and under the "System Administration" go into "Startup and Shutdown"; here you have a certain degree of control on what should be started on boot. Be sure to navigate all of the three tabs because each one contains a different set of possible startup apps and services.
You may find this a useful read: http://userbase.kde.org/System_Settings/Startup_and_Shutdown
You can also try to go into the
Hope this helps!
There are tons of posts about this topic but the developers acknowledge there is a lag in the startup process, look at this bug.
My tips: use preload, disable unused services (cups, nepomuk, bluetooth), system startup is improvable but starting KDE is the elephant in the room, there is no silver bullet for this.
The best I could do is activating the automatic login in kdm and when I power on the pc it starts and doesn't stop until fully operational.
Change this in /etc/kde4/kdm/kdmrc