That harshness that burns your throat is usually caused by a hotspot in the coil wraps, in other words you got some of the coil wraps touching each other or too close to the side of the atty inwhich they shouldn't. The coil wraps should be evenly spaced in the middle of the head or as in a microcoil tight together, the opposite.
Take a pin and a few minutes on youtube to see what they should look like and poke and praud till the coil wraps are evenly spaced. That should take care of the burning of the throat.
As for the gurgling replace those flavor wicks with something thicker and longer (cut the wick from a old top coil atty) to plug up the gap between the stemcap and the top of the wicking. Purchasing some 1 and 2mm silica wicking with your next vape order is a good idea to have onhand if your intending on using the stock heads without rebuilding them and just replacing the stock flavor wicks with better.