Ok first off let me just say, I applaud the effort you put into this idea/suggestion post as it is nicely detailed and explains thoroughly what it is you're looking for. Now for the bad news, the loan part of this would never work, because let's face it, we have absolutely no way to force someone to repay a loan so it would be very easy for someone to use several accounts to obtain loads of money. There may be some ways to combat this, but even so I don't see much point offering loans as the houses don't cost nearly realistic prices, so your only huge expense is cars which you should simply earn enough to purchase for yourself, a loan of $25,000 would hardly help for this.
Moving swiftly onward to your insurance idea... It's not bad really, but how would the insurance company know what items you have in your home? Also how would insurance really charge their premiums? It would mean I would have to figure out how to make it decide on variable rates as so it creates a profit margin otherwise people are simply repairing their car cheaper than they are now, which I don't really agree to. Additionally people tend to wreck their cars far faster in this gamemode, either as a result of their own negligence or that of others, and there would be no way to work out a deal with other person's insurance to have them pay for your car, so overall it just becomes a mess and impossible to code, as insurance companies have had to do this for several years and they still have to constantly change rates to accommodate for everything. And if it's run by players, just RP it now, I don't see the problem. However, if it could be used as a scam, that's exactly what every player would do, you would be hard pressed to find any legitimate insurance company then.
So overall I see too many issues and not enough purpose to these ideas at this time. I will leave the thread open for now so you're welcome to discuss it more if you can answer some of it. Again though, I like the amount of detail you have tried to give this suggestion this far.