Here's a list of what I stopped on my colorfly g808 and everything still runs ok.
Never disable youtube. The phone goes mental and has a pop up box saying its stopped. It's very hard to get back working.
com.android.app (possible built in spyware)
voice unlock
voice command
browser
videos
talkback
branding provider
com.android.os (possible spyware)
street view
google app
music visualisation wallpaper
exchange services
live wallpaper picker
google text to speech engine
bubbles
email
maps
oobe
magic smoke wallpaper
fm radio
phase beam
mtk live wallpapers
com.android.wallpaper.holospiral
hangouts
video favourites
black hole
keep
home screen tips
basic daydreams
google+
gmail
tags
android live wallpaper
face unlock
chrome