I highly recommend eloping before the wedding, but I would strongly advise you to not keep it a secret. Doing so will lead to many hurt feelings and unnecessary complications. We went to the court house 6 months before our big formal wedding and just did the ceremony with a judge (witnesses are not required where we live). We liked having the day to ourselves, without our families (who we love) ruin things the way they ruin everything else with lots of bickering and other things that I probably will need therapy for. Another big reason for doing this was because I wanted to be on his health care plan, which is so better than my own. From that standpoint, our families viewed it as us just taking care of some practical considerations, and not us wanting to leave them out of anything. We told our parents and friends before hand so that they would know and not be hurt later. We did not keep it a secret, but we didn’t tell every guest at our wedding, we figured our parents and friends would tell people anyway.
Eloping does allow you to separate the wedding day craziness and family BS that will accompany it, from the actual event of getting married. We were so relaxed the day of the second wedding, because we had been married for 6 months already (but we lived togther, so it was like we were married long before that). I will say that while the private ceremony was very special, saying our vows again in front of everyone was so great, and it really made things feel official. Being married already did not detract from the excitement or enjoyment we felt at the big wedding.
We had a non-religious ceremony at the second wedding that we wrote ourselves and the Groom’s father performed. He is not ordained or anything, so it was not a legal ceremony, which we didn’t need because we already had our legal ceremony. This was great for us because we didn’t have to hire an officiant, and having a family member read it was very special. If you are having a Rabbi for your ceremony, I would talk to him or her first to make sure they know you are getting married before hand. Do not lie about it. I suspect that it will not be a problem, and it they prefer, you can say you are renewing your vows or something. Keep in mind, you will be legally married the day you sign the marriage liscence, and therefore the Rabbi cannot file for a second liscence. You can’t be legally married twice. So many people end up signing their marriage liscenses on a different day than the actual wedding anyway, who cares?
As you have seen, people have very strong reactions to this sort of thing. I posted about our elopement on weddingbee before we did it, and some commentors felt free to tell me how horrible I was for doing this. People will tell you it will ruin your big day, or some people will insist on telling you that your second wedding is not a wedding, but is a vow renewal, and the calling it a wedding is a lie. Ignore these people. We referred to our second wedding (with all the family) as our "fake wedding", and to us it didn’t actually mater what people called it.
Since you will be married on the same day but a different year, you don’t have to worry about your anniversary date. In terms of deciding which day we want to celebrate as our anniversary, we decided that we have two choices and we can decided on a year by year basis. Our legal anniversary is in May, which is great for us since our other weddin is in November, which is full of birthdays and holidays. We don’t have anything going on in May, so it helps us spread out our celebrations for the year. Also, if my husband forgets our anniversary in May, Ipromised him he gets a do-over in November, and he really likes that.
Good Luck and Congratulations!