Hey guys,
I'm not sure this solves your issues. I found [https://github.com/dokterdok/Continuity-Activation-Tool|this] on github a few weeks ago and it worked great.
If you happen to be on the beta release program for Yosemite, you'll have to re-run the install script every time you upgraded. I haven't seen a performance decrease nor a battery life drop. Problem is that it requires an extra bluetooth dongle, certainly precious resource on these laptops.
PM me if you have questions.