Just to confirm, is Ancestry visa classed as a "work category"?
Yes it is as you are expected to come to work and have to support yourself without recourse to public funds The rules are fairly flexible but one of the requirements it that you intend to work or seek work . If you do not work at all I do not think you would get ILR under this category.
I am full time employed so won't be a problem, from what youve told me I can be outside of the UK for 90 days per year to safely guarantee my citizenship in 2015.
Thanks for your help.