Suspension and chassis geometry is a bit out of my league too, but common sense would suggest that what you do to one end you must also do to the other, just to keep the balance right. Like, if you drop the rear ride height an inch then you should do the same at the front.
Not sure if altering the steering will have any effect in compensating for a drop in rear height
To diverse just a little from the question, and maybe a little contradictory to mav's views (sorry mav!), but I really don't find the bike twitchy after changing to the steeper rake. The bike turns noticably quicker, and theoretically should be twitchy, but it just isn't! I wouldn't try it unless you've got a damper tho, and certainly not to compensate for the ride height.
Do what CK says - get platform boots!!