I read the entire thread, twice, to digest. Please tell me if I am incorrect. Oh right, you will. 
I think DLA and PIP are not means tested and whether the person is working is not important to the scheme either. I don't think that matters, everyone deserves health care and related services.
The disabled person receives a certain set sum, weekly, to do with as they wish. One third of the DLA PIP people enter the 3 yr car scheme, using their DLA Motability funds to a car.
Free school lunches will still be available for people who need the help and others may buy school lunches for a fee or take a packed lunch from home.
Parents who can afford it will be paying for their children's lunches.
Affect to taxes, after the election. I copied from durhamjen Sun 21-May-17 19:06:49 (because I could not do the maths) "If the Tories get back in they will change the tax thresholds, so that the change from 20-40% is at £50,000, not the present £45,000. This means that those who earn over £50,000 will get a rebate of 20% on the £5000, which is an extra £1000. At the moment they pay 40% of that £5000 between £45,000 and £50,000, which is £2000."
Not clear to me, the winter heating allowance will continue without means testing, maybe?
To dementia tax, I do not know, not clear at all to me.