Not everyone can afford to buy a house, whatever incentive is offered. I think there should be some form of rent control and longer tenancy contracts, given that so many people now are renting.
The 5% deposit may seem a good and attractive idea but if the interest rate goes up and people have a larger capital amount to pay back each month it could become a problem.
I agree with those who say council houses should not be sold - not that there are many left now. About 15 years ago I remember quite clearly seeing a report about London ex-council houses being sold for huge amounts. One young man sold his house in Hackney, bought a house outright, a little way outside of London, and an expensive sports car. It didn't seem right to me. Also, a very significant proportion of ex-council houses are now in the hands of private landlords. So much for the "property owning democracy".