Associated creditors are dealt with in various (and unpredictable) ways by other creditors: Sometimes they main creditors will ask that the associated creditor steps aside for the duration and gets no dividend. Also associated creditors votes are treated differently, hhich someone with more detailed knowledge would need to explain.
Tesco were one of my ex's creditors when we went into interlocking IVAs and voted 'yes'. A good chunk of our debts were incurred in the months approaching the IVA's --- in many cases, by then, most of us are living off credit !
The IP sees bank statements, but will report to creditors if there is anything they should know -- gambling being a pertinent issue, if, in their view, it is, will be addressed.
F&F vs. a full term ? : Usually a F&F proffered during an IVA is based on the amount the creditors stand to get in the long run, so is based on 'remaining payments' --- A usual dividend in an IVA seems to fall around 30 - 40%. So, for ease of maths, say you owed all non-associated creditors (we won't mention associated creditors for this exercise) £10,000 and are Ms Average. Your dividend at 40% would mean you are paying creditors back £4,000 plus fees, so total IVA payments, over 5 years, would be probably in the region of £6,500. So a F&F for a £10k debt would be based on £6.5k --- this is all, however, smoke and mirrors as there are so many variables, not least of which would be what affordable monthly payment was arrived at.
Yes, I am still here ( at least for the immediate future ) and you are more than welcome.