Legalise all drugs and tax them. Use every penny of tax paid on them to fund rehabilitation and direct advertising of the dangers (in real non scare terms). This is a win win win situation. People who do this to themselves won't be cast out of society. The dealers with guns will go away and the drugs themselves will pay for the rehabilitation programmes. Label alcohol and tobacco as drugs and treat them the same. Ban all advertising of all drugs (including alcohol) to protect people who want to leave the drugs alone. Have a legal age of use based on science rather than politics. Impose strict penalties on publicans and off sales who sell to young people or to people who are completely wasted. Add a minimum price per unit on all drugs – including alcohol. This extra tax should go towards rehabilitation.
Legalise prostitution but impose strict procedures to ensure the people involved are protected .Tax it and pay the money into both welfare schemes (such as education and training and drug rehabilitation programmes. Impose proper sentences for people caught trafficking (i.e. life in prison). Make all brothels closely regulated and controlled. If people are brought to the country and repeatedly raped many times a day when found they should be treated with dignity and allowed to stop here with lots of help rather than treated as illegal immigrants. Severity punish anyone working outside of the state control.
Why is this idea important?
At the moment drugs cause use social problems but these are hard to treat because they are illegal. The legal status causes horrible crime to be involved. If they were legal this would not happen. also what people do to themselves is ultimately up to them. By legalising and taxing the drugs with all money fed into rehab, society would be allowing people to do what they want while at the same time organising a safety net to protect the vulnerable. Legalisation would also allow heroin addicts to be treated with heroin which would most probably work better as part of a rehabilitation programme. AA and NA are good organisations for this and could be used directly to supplement the state schemes for free (they won't even except money if offered so they truly are voluntary)
The legal status of prostitution seems to me to be directly responsible for the violent criminals and exploitation of vulnerable woman as well as the repeated rape of trafficked woman. Legalising would reduce and perhaps illegal this side while giving the people involved protection and help out of their situation should they want it. At the end of the day if people want to do this though and it is properly concentrate then society has no moral right to stop them.