every time you get on a bike there is a risk,my attitude is i don't add to the risk by not wearing a helmet,and maybe not drinking alcohol ,thats my choice as for, diy where in all in hell did that come from,what personal safety equipment is down to the job you are doing,I've been on sites and got shards of porcelain tile in my eyes,and have had to had it removed all due to not wearing goggles,my weakness is my eyes so yes i wear safety glasses to ride as often been hit in face by flying gravel, I am no safety angel, just part of my day to day is to risk asses grade and control,as i have said i couldn't give a toss if people don't wear a hemet,or ride with a bottle of absinth in there bottle holder,if they decide they are happy to do it, then happy days for them
The risks i have taken over my early years was incredible , high roping,climbing,to name a few,that was then I aint got the bottle any more,getting older wiser!! and more cautious
The relevance is that there are many activities that carry a risk, but that risk is sometimes so low as to make it unnecessary to take action.
Yes, having 2 or 3 pints before cycling does increase the risk, but does it increase it enough to warrant a specific alcohol limit such as we have with cars? We already have a law that makes it illegal to be not in control of the bike - do we need a specific limit? I would say no.