Welcome to SR Tonya. Your intentions are surely good, but as has been mentioned already, he will need to do this for himself - and your actions will really have little or no effect on his drinking. Alcoholism and addiction are very self-serving, and most active alcoholics will lie/cheat/steal and do whatever they can to feed their addiction, even to close family members and friends.
Your past actions did not have any affect on his addiction - that is his responsibility and choice, and his alone - to make. Regarding your first 2 questions, kindling is real and it is lifelong. Just like addiction - once you cross the line, you can never go back. Regarding your 2nd question, you will need to decide that for yourself - but as you've been forwarned - being involved with an addict can be a very painful and empty life. Also know that there are just as many addicts that never seek help and keep using/drinking as those that stop - so the odds are against him.