1) yes
2) yes
3) no… only the first inquiry will ‘ding’ your credit. (and its only a few points) The way it works is the credit bureaus look at the kind of inquiries and if they are all mortgage brokers, etc., they only ding you for the first one. It’s not enough to have a negative affect on your FICO score.

To give an accurate estimate they will have to run your credit, otherwise it’s just guesswork on their part.

1. Yes, your actual rate will depend on your actual credit report and the current prime rate for the day you lock in.

2. Yes, they will all want to run your credit

3. Yes, “inquires” do lower your credit score.