[Seerah]

All these table.inserts are totally unnecessary. Not only is it both a global and table lookup, but it's also a function call. At least this section of code only runs once, but it is much quicker and simpler to read if you just fill in the table when you create it.

local eventTable = {
     'CHAT_MSG_SAY',
     'CHAT_MSG_YELL',
     --etc.
}

Not a big deal, but why do you have two separate frames? (f and g) You only have one event registered to g, so you could just condense them. This is the whole reason why the event parameter is passed through to the function.

f:SetScript("OnEvent", function(self, event, ...)
     if event == "UPDATE_CHAT_COLOR" then
          --do this stuff here
     else
          --do the other stuff
     end
end)

Why are you calling ChatFrame_AddMessageEventFilter for all of these events and hiding all of these messages from chat? By doing this and then using your commonChatEventHandler and only adding a message to ChatFrame1, you are overriding any user's preferred location of displaying messages.