Also, never make a small claim, otherwise carrier will raise your premiums next year. 

For instance, one insurance broker told me that just the presence of "aluminum wiring" reduced the number of insurance carriers that she could place me with from 25 to 3. 

Structure - if you are moving forward with wanting to put your REI into separate entities for asset protection, then you will want to have 2 separate insurance programs.  1 for your personal home, auto & umbrella and 1for the REI.As for insurance carrier recommendations, it depends on if you have a SFR, retail building, multi unit, etc.

I have reached out to 5 insurance brokers and so far have received quotes from safeco and allied.Allied quite is almost double of safeco for similar coverageI haven't yet found a broker that is aware of any insurance carrier that offers a single deductible across different properties.

My first insurance carrier (USAA) limited my standard fire/liability policy to only 4 properties so I just went out and picked up a Liberty Mutual policy for the remaining 4, but now I'm in the same problem since LM won't insure more than 4 either.

In my case it was Bryant AKA Carrier and I couldn't buy the parts anywhere.

When I moved here from NYC I changed my phone carrier, another credit check, I opened a credit union account, another credit check, I think you get the idea. 

This is not just my personal policy; it relates to what my insurance carrier deems high risk. 

It looks that not very many carriers will insure in that area.

I don't think that's anywhere near an apples to apples here because, by design, that termination fee is meant to make the carrier whole.