Then by all means, go have some "fun" then! (It's fine, I knew what you really meant)
Jests aside, all I said was I feel like I've gotten comfortable with my Drk, I didn't say anything about being a "master". I also never said anything about going over the MP cap. The whole idea behind what I said was to basically go from low mp back up to near full in the time it takes for Dark Side to go through it's CD cycle and at no point will you ever be over your mp cap lol. Sure, you'll possibly loose a very small amount of dps, (because all you need to do to refill it back up to full is to do the power slash + syphon strike combo then back to power slash and another syphon and most of your mp is already back from that) but you'll recover mp quicker, which is the whole main idea about the method I use. It's a quick burst to refill MP and that's it.
I'm not going through full sets of rotations just to do this like you seem to think lol. You CAN leave Dark Side on while you're doing this, but it takes longer to refill your mp if you do. And all of this is assuming that blood price is on CD and, again, you just need a quick way to refill your mp.
P.S. If you you'd like to stay in blood weapon for a little longer once you've got your mp where you want it to be, then you can easily turn Dark Side back on and slam your target with a few Dark Art boosted abilities. You'll already be nearly topped off when Dark Side has been reset so there probably won't be any harm not to unless you need to conserve mp (and aside from that, you'll still be recovering some of the mp you're burning up from Dark Arts). Shadow Wall is also good to use while you're Grit is off in order to cover your lost defenses.
P.S.S I take what I said back about it being a dps loss....because by recharging your mp up quickly this way, you're more able to recover lost dps by using multiple casted Dark Arts buffed attacks. If you don't like the way I play my Drk then that's totally fine with me. It works and I don't have any MP issues and my dps is solid so I've got no complaints. It's a fun job.