While having a good credit score won't immediately qualify you for a loan, having a bad credit score could disqualify you for a loan.
Lenders and loan officers are likely to be busy with customers who'll trust them to allow a credit inquiry---until then, you're just browsing or window shopping in the eyes of a busy LO.
Answers to many basic questions can be found everywhere including here.
I'm not sure what type of questions you have but we just got our loan from DCU. I called them with plenty of questions before even applying and their employees were more than willing to help. They were very straight forward with their answers regarding their process and requirements. I would highly recommend checking them out.
It sounds like you need to simply keep searching for the right LO and lender that will meet your needs. Don't get discouraged if it takes time to find the right one that will do so. Rome wasn't built in a day, but obtaining a mortgage isn't Rocket Science either.
If your income has been consistent and is easily verifiable on your tax returns for the last 2 years, than your loan will be relatively straightforward; and, coupled with 700+ credit scores, and a good debt to income ratio, any major bank will loan you money at fairly great rates.
In this case, there's really not much to inquire of lenders.
If your loan has some challenges... than, take the advice to retain a Realtor and use their preferred mortgage broker. But, keep in mind that it isn't free to push loans through; so they will absolutely be taking advantage, in the form of points.
I am more than happy to answer any questions you might regarding getting pre-approved for a mortgage. If all information is received I can send a pre-approval same day. Message me your contact information and I will reach out within the day. Communication is key in building a relationship but also to make sure your getting the best deal and know what your getting into.
If you are doing FHA and have student loans, it is a must that the lender use 1% of our outstanding loan balance as your monthly payment. It is only conventional loans that can use the payment that is reported on the credit report. I am going FHA and my loans have a $0 payment on my reports, but because my outstanding balance is $60K, my lender is using $600 as my monthly payment amount.
Conventional loans also have stricter DTI requirements, so it could be that FHA would be a better fit for you in that area as well. Our lender has a program for first-time buyers for conventional loans that has income requirements. We exceed the max income requirement and because our mid scores are less than 700, FHA was the better route for us given that the mortgage insurance would cost less than conventional's PMI rates.