Why not make them a bit more useful by giving runners the option to put their ICE details on them. Ie. Name and number of contact person so in case of an emergency it's obvious who should be called.
Having said that I'm still very happy with the humble safety pins so won't be buying any eventclips for now.
I would think you have enough time to train for the marathon in April. Think its a bit too early thinking about pulling out! If you start a 16wks marathon plan nx week it would take you to end of March plus allow some extra time for injury etc. I have done the Bupa HM and Marathon plan and they worked for me.Sorry, cannot give tips for the cold problem as I don't really catch . Good luck
I would maybe try them but really put off by the advertising on them. If they would come in plain colours or if you could get you image on them it would be much more appealing to me. I also don't fancy trying to get a hole in my number first before I can use these.
So far I had no trouble with safety pins and did not find any holes in my shirts which were caused by them.