Fx-8350 user here. Changing bitrate from 24bit48k to 16bit44.1k (lowest possible) was not even noticeably impactful on the amount of stuttering. Changing from DX11 to DX9 helps audio but it hurts graphics and at the end of the day the audio issue is still there.

I don't think LatencyMon results really mean anything....I am getting spikes over 2k µs range even without any applications running, yet I've never experienced audio anomalies while using any other applications. With FFXIV open it did spike up to 4.6k µs however, but the audio stuttering was happening even when it was consistently showing measurements <1k µs.