The tone of the article is one of humorous self-deprecation, which is quite a common trait amongst Brits and Australians; to me, the inclusion of "a wife" in that sentence seems no more strange than his mention of "long pub lunches" as a highlight of his previous career in industry.

That he lists "several pairs of trousers" in the same list of accomplishments as a Porsche and investment properties should be a clue.

Disturbed? Not really.

Sounds like the author was pointing out his own flaws in terms of what he considered success at that point in his life.

I think/hope he meant the extra material accumulation commonly associated with being married.

I think he is alluding to the fact that a separation or divorce is most likely what prompted all this and perhaps his wife was a driving factor in their mutual accumulation of material things back then.

No. He's realized the errors of his past ways and his thinking which included treating a human like a possession that is slightly more valuable than a few pairs of trousers. That's the joke. Sometimes jokes are hard because they reveal the dirty reality underlying them.

That bothered me, too