Hip fire is fine as is, as its not meant to be easy to kill weapon for cqc.
Basically my version of balancing for DMR would be
1. OHK headshot within 15m. Doesn't matter whether its going to be increase in max damage, or increase in headshot multiplier. Though, leaning towards more headshot multiplier.
2. Maximum three shot kill at any range (except SKS or the sort). I think this one is the most important change that needs to be made, as its easy to ignore DMR and just run away as of now.
3. Increase RPM slightly, or decrease recoil slightly.
If DICE decides to fix DMR characteristics, its not going to be massive code overhaul or anything, but mere few data point correction (just like changing cells in excel spreadsheet). Its not really going to take much man power, unless they are going to extensively test it on their own (which I highly doubt).