My own experience of factors over the course of many years has led me to the conclusion that they are a waste of space, far more interested in whatever prestige developments they are involved with than the closes they have on their books.
Having said this, I am also sceptical of self-factoring as an alternative. Maybe this works among middle class tenement dwellers in the West End. However in my opinion the vast majority of owners don't give a toss about common maintenance. The sheer pigheadedness and wilful ignorance I have come across in this respect over the years is absolutely staggering. Most of them genuinely don't think it has anything to do with them. They will spend large sums of money on their own flats, yet plead poverty whenever they are asked to share the cost of even the most menial repairs. I have given up trying to convince people that a reasonable sum of cash spent on preventive maintenance in the present is the way to avoid huge bills when things get so bad that they have to be attended to whether you like it or not. At which point of course everybody else is to blame for the problem.
Perhaps matters would improve if factors did something for their management fees and acted in a more pro-active manner but I doubt it somehow.
As for the insurance question, I would like to think Crusty is right but I suspect that any insurance company would go through hell and high water to try and prove that a problem which has been the subject of a claim was caused by poor maintenance on behalf of the owners. Not that this would be hard to prove considering the self-evident condition of the majority of tenements in Glasgow.
I'd better stop now because I could go on in this misanthropic vein for hours.