@Juan Martinez
What the lender is doing is very normal. Most lenders will only lend if it looks like a good deal. It is expensive to take back a property so that is not the goal at all. A good lender should work with you and provide as many resources as possible. However, they should not be running the property or making finishout decisions, only providing advice or a list of names of possible contractors. You should still be free to do what you want and choose who you want to work with. If that is not the case, there there could be some legal issues with you working as an agent of theirs and not independent.
I think when you are staying LTV you are actually meaning LTC. I get to this conclusion because you are stating that they are lending 80% and you are paying 20%. That is a loan to cost equation. When looking at the maximum loan they are willing to give based on the ARV, you are looking at LTV (most lenders are between 65% and 75%). As for LTC most lenders fall between 80% and 100%.