Please help me understand Variables in Rental Property Calc's

[Sean C.]

I've started to try and analyze properties, to get into the practice, however there are several variables that I do not know when it comes to estimating.  I'm aware these are very beginner questions, and appreciate any help you can offer

1. When you figure out the Interest Rate, how do you determine what number to use?  Do you have to go figure out what banks would charge *you*, as in go get preapproved/prequalified before this is analyzed?   If not, where do you recommend I find the Interest Rate information, so that I can have a carefuly considered analysis?

2. In Insurance, how do you come up with your numbers?  Do I have to call an Insurance company with the property address for every individual property every time, to get that estimate?  Or is there a way to figure out a comfortable guess.

3. Is there a way to figure out if I pay the utilities, or the tenant does?

4.  I have heard of Property Management fees, ranging from 6-8% in Podcasts.  How do you find the most accurate figure for your Property Management Fees?   Do you have to call several agencies in your area, and then average them to find out what they are? 

Thank you in advance.  I'd love to learn how you guys dig up certain details.  I feel like the better you understand the numbers, the better you can analyze these.

Best,
SC