Do you have a cite for that? Of the 6 mortgages I’ve had, only one was ever sold.
Here’s one cite - says the originating lender may well continue to service the mortgage, even if they sell it behind the scenes.
Has your credit improved since you got your last mortgage? A year isn’t very long for your mortgage offer to change. The difference in interest rates usually comes from people’s credit scores in general, not because banks are competing so much, the interest rate for fixed mortgages is usually pretty standard wherever you go, maybe varying a quarter point here and there. You might find a slight difference between banks, but I would be suprised if you could go down 2 whole interest points in a year without some change in your credit or income. Especially since you don’t have any equity.
It is possible to roll closing costs into your refinance, but they are probably not going to do that for you if it makes your mortgage higher than your house is worth. So if you have, say, a mortgage for $100,000 and your house is worth that much too, the bank doesn’t want to roll $3-5000 of closing costs into your mortgage because then you owe more than your house is worth. Did you pay your own closing last time or is that already rolled into your first mortgage?
Unless you got some kind of horrible crappy lender last time, your approval process a year later is probably going to be very similar. One other option is to try to find a lender that does manual underwriting. This means that they look at more than just your credit score to approve you. So if your credit score is bad because of one mistake, and you can prove you are better now and pay everything on time, you might get a better rate.
You can always call around though, it doesn’t cost anything to get quotes. But I agree that the super low payments you see advertised are always for teaser adjustable rates, or interest only loans, or the like. You just can’t go from a $1200 payment to a $600 payment without some kind of screw-you-later deal.
Does anyone know about Amerisave.com? Are they as good as Lending Tree or CountryWide?
Probably about the same, unless simply owning a home helps.
Seller paid closing costs.
I have my suspicions about the lender 
Maybe it’s improved some - simply by having a year of proving you can make payments on time. Also, what about other debts? Do you owe more on credit cards compared with last year, or less? And if you still have the same cc accounts, the length the accounts have been open should help. Have you continued making payment on other debts in a timely manner?
Just saying, you may be surprised at how your credit score has changed in a year; it’s surely worth plunking down the fee to get your FICO if there’s a chance it may help you get a better rate.