It could be a little better honestly. I pull 420 dps on a dummy in a 5-minute parse so I would estimate that you should be doing around 380-390 dps without Foe Requiem. I have pulled around 410-415 dps with Foe Req, food, pots, and no i115 weapon.

What I would suggest to you, is to keep auto-attacking the boss, especially when you switch targets, cause that's around 5-10 dps right there you're missing (my estimation might be a bit off). You can also place garuda-egi on the tower spot so that it won't get pushed around by the mines. I would also suggest saving 1 stack of aetherflow to bane onto dread and make sure to put up shadowflare and miasma II for when dread is about to spawn or has spawned. Use miasma II when you also have contagion, so put your pet on obey. And clip your dots at around 2-4 seconds and use ruin II sparingly. That's about it.