Decided to re roll another character, delete heathfire and Dawnguard, then re install them.
Lakeview was unusable due to freezes and my set up was - Greenhouse, Armoury and Alchemy lab (all fully furnished) Safe to say i won't be doing that again.
Edit: Forgot to mention I'm only interested in the opinions from people that have the full set up, because i too had no issues until i had fully annexed the house and furnished it. So with that in mind, if you only have the basic house, there's no point adding to the thread as i know the house is fine during the inital stages.
Any help greatly appreciated.