TINK, before I start my reply, I'll say I do agree w/ you for the most part. This post is largely correcting/opinions on some of the finer points from my experiences/studies.
You doing fine coming off benzos is rare. Most have issue with it, even if not using recreationally (as a general rule, it's fair enough to assume most on these boards use recreationally, at least a little, even if in conjunction with proper therapy).
Cyrax is right and wrong. Going from opiates to benzos is a good idea for some, if you can swap your heroin addiction for a 1mg/day xanax addiction, that's a good idea. If you're trying to kick a year-long, 10-40mg oxy habit, I'd heavily advise against starting benzo's, you'll likely find them to be a similar issue to opioids re tolerance, addiction, and withdrawals.
In regards to why most people slip back into a previous addiction, in the simplest terms, it's because of the exact same reasons they fell into their first addiction. This is a situation that varies by individual, however, I disagree with your "dealing with emotional issues" as the central theme of addiction. First, the chemicals themselves are, naturally, the "root issue" of addiction by the very nature of the situation - without the chemicals, no addiction can exist. Now, for someone who's gotten off of the chemical of their choice, there's many things that can cause relapse. However, it seems by far that the two biggest factors are simply wanting back on the drug (which can definitely be caused by un-handled emotional issues, but can just as easily be caused by a desire to be high, by obsessive behaviors, or even situationally, ie everyone they know does it and it just "makes sense" to use again in their eyes), and secondly, and I feel this can be far bigger a factor for many(most?) addicts - they don't know a life outside of drugs.
See, once you've gotten to the point of real addiction, your life is changed. I don't mean that in the physical sense, or even necessarily the mental sense (though both are absolutely factors), rather I'm referring to "life-situation". When one wanders down the path that ends with addiction, they've typically done some/most/all of the following: replaced their real friends with people who use/sell; wasted years getting/using/selling, and thus destroyed their resume (ability to move onto something else); burnt through their money and possessions (ability to move onto something else); burnt bridges with family (ability to move onto something else); <sometimes> got into legal issues (ability to move onto something else).
Unfortunately, the very circumstances that one finds themselves in once addicted make recovery extremely hard if they aren't helped. Once you "live the life" for a long enough time, finding a new path can be so hard that it seems impossible. One may detox, and be 6mo clean, but if they're still living in the same area, around the same people, not able to make progress in a different area, well, going back to the old path just happens.
(I know that all too well - I'm currently clean(enough, wouldn't say 100% if I so much as drank coffee, I'm really about absolutes lol), and while I've been able to do a majority of what I had to in regards to distancing myself from those who used in addictive manners (which the majority of the people I knew did, when I was addicted), and as far as work towards "normal" life, so to speak, it's absolutely a very tough path to get onto the "right" track. Given how hard it is, many cannot do it - and that's BEFORE you factor in the physical-dependency/chemical-addiction aspects, once you put those in there, for many/most it becomes a situation of helplessness, where they really don't believe they can get back to any kind of "real" life, and when that's compounded with the ability to use their fav drug again, it's pretty much over at that point :/
Drug addiction treatment/recovery is an area that needs HUGE amounts of progress. It's really sad how little help there is for people who end up relapsing when they very well could've gone on to be good, productive members of society
Thanks, AP