It will be in everyone's best interest if recreational drugs (including alcohol) are made illegal.
I've read many insightful comments and ideas in this thread, but I find one thing to be missing from the arguments I've read; the fact that prohibiting a substance in a place where it has never preciously been available, is very different from prohibiting the same substance in a place where it's already available (legally or not).
On Earth it's relatively easy to grow large amounts of marijuana, or produce large amounts of alcohol, which is one reason why they can be so easily acquired on the black market. That won't be the case in Asgardia, so there won't be the same problem of people acquiring drugs and alcohol from an unrepeatable source, should they be made illegal.
Smuggling is still something that could happen, but considering the very restricted amounts of cargo that can (at least at this time) be transported in to space at one time, the amount of goods that could slip though customs (or whatever you want to call it) will be minimal. Here on Earth you could, and it is done, smuggle several kilos of cocaine or pot into any country. On a space cargo ship, even 100gm of a drug, or one small bottle of alcohol would be noticeable. Some might still slip though, but it's going to be much more manageable than the effects of unrestricted access to alcohol and other recreational drugs.
I love wine, and if moving to a space station I would like to be able to have a glass of wine from time to time. However, most of all I want to be safe. Knowing what we know of humans' lack of responsibility and consideration for others, and how we constantly abuse both legal and illegal drugs (not only alcoholics and addicts), my vote will still be for the ban of all recreational drugs/substances.
The risks of the potential damages caused by one person abusing alcohol or drugs, so very greatly outweighs the gains for people using it responsibly. Secondly, there are an ever increasing market for non-alcoholic beverages so, if like me, a person would miss the taste of alcoholic drinks there are options. Options that don't include the possibility of a person becoming intoxicated and in that state causing damage that could be life-threatening to everyone on the space station.
Living in space (at least at this point and the foreseeable future) will not be like living on Earth. What we can eat and drink, and what forms of recreation will be available to us, and how often we can engage in these activities will be different from how it is on Earth.
Life in space won't entail as many choices as life on Earth does. If a person is not ready to give up a lot of the comforts and luxuries, as well as basic things we take for granted on Earth (i.e. showering as often and as long as you want), for the excitement of space explorations and research - the chance to experience a different way of life - then perhaps it might be better for such a person to serve Asgardia through a job posting on Earth.
When Asgardia's space station becomes a reality, initially, most of Asgardia's citizens won't be able to go there anyway. There won't be enough room. It would be in Asgardia's best interest to send those who value the work that can be done at this station, over the consumption/use of recreational drugs (including alcohol) to live on the space station, and leave those who feel that recreational drugs are something they must have in their lives to carry out job positions on Earth.