upgrading wii after a downgrade

forgive me if this is a stupid question !!
I downgraded my wii from 3.4E to 3.2. All I want to do is play back up discs and dvds.
I installed the gamma pack, but as i understand i only really needed to downgrade if
I wanted to run starfall ? is this a correct assumption ?? If i erase homebrew and start
again I presume my wii wont go back to 3.4 unless I upgrade ? or is it returned to
factory state when I erase homebrew ??
if i then do a system update from the internet will it update to 4.0 ?? and if so can i downgrade
from 4.0 to 3.4 ??
sorry for so many questions but being a newbie not really sure what to do.
reason i want to return to 3.4 is that i have to play all discs now back up and originals
through the home brew channel !! as most will not show in the wii menu as they used to !
thanks for your time and patience for reading this post. help much appreciated
Paul