Yes, I absolutely recommend using a tape recorder!!! I would also strongly recommend that you do so--and follow through!--with the court in mind, as you said. I made the mistake of not following through with this in a meaningful fashion...in court...and instead presented what little bit of recorded evidence I had gleaned to the elders. [The context of it was to prove his abusive rants aimed at me, and in front of the kids. Plus it proved, definitively--which the elder acknowledged--that my ex had lied to the elders during their investigation into our marital matters (my abuse allegations).]
But then one of them said to me, "If he had a history of getting violent, I'd be concerned how [your husband] would react if he knew you'd been following him around with a tape recorder." I backed off letting them pursue the judicial action I had been requesting then...walking away feeling further intimidated and discouraged (after all, it was a legitimate concern) instead of feeling emboldened and supported. A couple years later, I finally gave them permission to use the recording and the elder's firsthand knowledge of my ex's lies about the events therein [the recording and the elder now comprising the 'two witnesses' necessary for judicial action to take place]. I never did hear of any action taking place. To this day, my ex has no idea that I was following him around with a recorder.
Anyway, at the very least, the tapes literally SAVED MY SANITY!!! I finally had some confirmation that the kinds of the things he would say and do really WERE as I had perceived them, and not as he would later re-tell it in his watered-down, twisted versions. It would leave me feeling a very fundamental disconnect from, and distrust of, my own sense of perception--hence, the increasing threat to sanity. I kid you not. IT SAVED MY SANITY!!! If recording your wife and the insane household goings-on never even makes it to court, at the very least, it will help you to stay grounded and sure-footed in the insane situation you are just about to embark on! Good luck to you. I really hope things with your wife level out.