Sspeed, keep in mind you may never get the subordination approval from the second lien holder, there is no law saying they have to grant it. It would help if you knew how much equity you have in the property now including the second so you can make an arguement for yourself.
That would depend on what lender holds the current second. It can take 48 hours or it can take close to a month. A few lenders we send business to no longer require a subordination agreement for an existing second and any time we have an existing second we send to those lenders to avoid the possible lock killing wait.