I am an atheist living in a non-Muslim country, in Europe, and I will tell how it looks from my perspective.
Starting letters, books or presentations with name of any God is extremely rare. The only situation that comes to my mind, is that priests sometimes start and often end their letters with phrases like "may God bless you", but "regular" people use such phrases rarely.
So the first thing with starting with "God" as a first word in any publication or speech is that such thing is very uncommon.
The second thing is discrimination. Muslims are quite often not much liked in non-Muslim countries. Starting something with the word "Allah" may then create negative reaction on people.
You can find people that will not react any negative, if you start something with the name of God at the beginning. Some may even react positively, as they may be interested in Muslims' culture. However, as of today, majority of Europe citizens are not so open on Islam and your action may take a different result than expected.
Summarizing. In my personal opinion, as an European citizen, using "Allah" in the beginning of letters, books or presentations may (but not must) bring negative reactions in open public. If you have non-Muslim friends who are interested in Muslims' culture, then they should react okay.
The best answer could probably bring a Muslim person who tried such things in public, who could tell us about his/hers experience.