the website said that the gt-100 can be used as an amp switcher to switch your amp channels.

my concern is, can i use it also as a pedal switcher if i'm going to use external pedals distortion to be exact. and can i create a patch that will contain the external pedals that i connected to the gt-100 along with the modulation, delay, and other effects that the gt-100 has?

Only one effects loop on the GT-100 but you turn it on and off on a patch by patch basis.
Gilchrist custom
Yamaha SBG500
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100

Cathbard Amplification
My band