Hiya Adele
Hooray for sister – anything or anybody that keeps you active and away from the constant niggling about gambling is good.   It helps when you are eventually faced with having to think about it, to be clearer headed and more positive..  
I think it is great that you are more at peace with yourself than you have been for a long time.   You are aware that there may be slightly stormier ***** ahead  but – here you, fully aware of the capabilities of the addiction and yet you are feeling at peace.  That is a woman on a mission.  
You are making the most of the calm ***** – you are gaining in strength. You are enjoying other things in life and dare I say it – not spending every day looking at this site which is not always a healthy option when you want to pull back from the constant buzz of hearing the addiction. 
I understand what you mean when you say that even if the gambling was controlled your husband might still have problems which would be, for many, unacceptable and that is something that only you can decide about.   A thief who becomes a CG and then controls their addiction will almost certainly still be a thief.  A CG who steals to satisfy the addiction and then controls that addiction will almost certainly not be a thief.  
The information as to what brought the CG to the professional has to come from the client, or loved one (if they are included), but the dissembling of that information comes from expertise, experience, understanding and years of training.   A good therapist/counsellor will help the client dig in to their inner self but if the client is determined not to allow the therapist in, the job is almost impossible – hence the requirement that the CG has to want to stop.  Having supported the client to dig deep and bring up the issues that have lain buried they can  teach how to use the tools for the future.      Personally I would go on recommendation – we have access to a lot more information on the ability of professionals these days and I would use every bit of it.    I went to a counsellor and a psychiatrist on the recommendation of my doctor – but I don’t think even my doctor had a clue about the addiction and the counselling made me feel worse and more alone than before.   The psychiatrist thankfully did help me understand that I did not have Alzheimer’s disease but after a time that information did not help either.  My problem was that I didn’t know what I was looking for  – but you do.  
With regard to how they learn about side issues – if you take this forum, the first post is solely about the CG.   It takes time to learn about the author of the post but I know a lot about you just by continuing along a path together.   You are an incredibly capable human being and you know what you want from a counsellor – even if you think you don’t.   I know I cannot tell you what to do but having found the right counsellor it is my belief, that the CG is better off seeing that counsellor alone.     It does involve a lot of trust but I know, for instance, that I would not have been helpful to the counsellors who gave my CG the ability to dig deep into himself for his answers and who gave him the tools to live his life in control of his addiction.    I believe that our recovery follows a different path and is equally important.   The paths might converge but it is better, in my opinion, that regardless of the outcome, the non-CG walks their path separately.
I think ‘you’ will know if the counsellor your husband sees is up to the mark.   When a CG changes they lay a massive burden down and the lightness that comes from that act is visible – especially when you are as aware as you are.
I accept that your husband may have looked sincere and humble and I believe that getting you ‘straightened out’ is the best thing you can do for you and for him – however ‘straightening you out’ is not his answer.   You are not being ‘straightened out’ so that you can live with and tolerate his addiction.   ‘You’ do not make your husband gamble.   ‘You’ do not make your husband look at ****.  
I find your words about wanting a ‘better marriage than you had before the addiction’ to be positive.   None of us can truly know when the addiction did start – the CG can usually only guess.   However I don’t find it strange at all that you think that if a better future is possible you will have the addiction to thank.   I don’t thank my CG’s addiction because it caused him too much pain but I do probably have a better relationship with him than would have been possible without adversity.   Many families have different adversities and working through them can create better relationships.   I believe that the addiction to gamble is one of the greatest adversities but can, if we allow it, be turned into a great education. 
Thank goodness for the slave driver.   It sounds as though you are doing a great job and I am sure the end result will make all the aching bones worthwhile.