I second not recommending heavy stuff up front. I have done a bunch of fully loaded trips, up to a month long, and have always used small front bags, and even then were always careful with keeping it light, as I did not like the feel of heavy steering, not to mention handling characteristics on fast downhills and around corners on downhills. Have toured most of teh Pyrenees mtns, have gone down the west coast of the US and purely from a safety angle, keep it light is my experienced opinion.
not to mention just plain old less work for you, being very minimalist for me came from doing my first big trip fully loaded (Gaspe penninsula, Quebec Canada) where I had too much stuff, and it wasnt fun on the killer climbs that I encountered--I learned the hard way.
its the old axom, like a gas that will fit a given space whether big or small, if you have large front bags, you're going to put [censored] in em. Again, from a handling pt of view, you wouldnt want big bags with little stuff in them being "shifty" or "floppy", nor as someone stated, why put a even bigger "sail" in front for headwinds.
only you will know after attempting a trip what weight is ok for you, or if having a big wad of stuff up front is a prob for you or not, maybe you take it easy on downhills, or whatever, but my opinion is to keep it lean.
Oh, Same goes for a handlebar bag--this really impacts your steering if it is "heavy".
last opinion--try to realistically pack your big as for a trip and actually ride the thing long BEFORE your trip, this may be an incentive to trim your stuff down. And IMO, no, you dont need a chain whip, or a big honking adjsutable wrench, or cone wrenches etc, (depending on where you are going that is I realize) One cooking pot, light plastic cup instead of your fav stainless one etc etc
All kinds of stuff adds up to weight, and riding BEFOREHAND with your god-awfully-heavy bike will show you what it really feels like. Hell, go up a good steep hill with it like this, and down too.