If you called the CAB and they didn't do a full benefit check for you, I'd complain because they should have done. The system is confusing at best the first time you encounter it and CAB should have gone through all your circumstances and been able to give you an estaimate of what benefits you should get over the phone - there is usually no short answer to the question "to what am I entitled?"
Having read thru it seems the major confusion is between contribution-based JSA - they will always check if you are entitled to this, and income-based JSA - they should also check whether you are entitled to this and you may well be if you are not a single person w/o disability, mortgage, etc. You don't get less help for working for many years (or shouldn't) but some of the help you get might be in the form of cbJSA rather than ibJSA at first, because the former is taken into account as income when they check your eligibility for the later.
You always claim ibJSA as a couple - you can't avoid doing so and if you try, for example by not declaring a partner's income you risk overpayment and allegations of fraud.
Even if you aren't eligible for ibJSA at first, for example because your partner has income, if you have a mortgage you might shortly become eligible because after a few weeks you may be eligible for assistance with mortgage interest ... the way ibJSA is calculated is that it starts off from a notional figure based on your circumstances from which your income is deducted and you get paid the diff ... if your income exceeds your notional figure you get nothing from ibJSA. Once you become eligible for assistance with mortgage interest that adds an extra bit to the notional figure so there's more chance your income won't exceed it. In my experience it's necessary to chase DWP after the 13 week period to make sure they reassess you at that stage - don't assume they will do it automatically.
Assistance with Council Tax dealt with separately and Child Tax Credits also a separate issue. Working Tax Credit affects ibJSA though, and can run on after work ends, or you might continue to be eligible if a partner works so be very careful!
IMHO if you get WTC and might be eligible for ibJSA there's no substitute for a proper benefit check as the question of whether you're better off speaking to the Tax Credit Office immediately or waiting until the end of the tax year is not a simple one. Problem is that (where I am at least) local DWP offices have stopped doing full benefit advice and just send people to the CAB. CAB are often short-staffed and overwhelmed and so people often have no access to advice at all or the presenting question gets answered without the requisite degree of delving and explanation. Very unsatisfactory.