Mei, if you wish to continue this arguement then you are more than welcome to find me on SL on either Joker, Finishline, Sharakkar, or a number of other accounts that I'm sure someone can point you to. However it is neither completely constructive to the whole point of this topic nor even necessary.
"The MS doesnt have any drawbacks involving physical damage, how does one express partial blindness ingame?" While off topic, this is actually a good question, but one that could be solved by a simple debuff that increases in its power based on either the number of Magyneko activations and technique uses or the length of activation. Also, as Mei stated, "Honestly, they can probably use it for as long as they have chakra to use the techs." This brings me to my next idea, that the Magyneko should automatically deactived once the user reaches 0 chakra, the same would of course go for the Byakugan, which leads me into my next thought.
Since, everyone is quite obviously against an indefinately active Byakugan, I have a different idea. Completely scratch my previous perma-active Byakugan, but keep the move that I suggested. Then instead of having the Byakugan perma-active the length of the initial activation could be based on the number of reborns into the Hyuuga, i.e. 1=10, 2=20, 3=30, and 4=40, of course they could be adjusted to an increase of five per reborn. Then in order to keep the Byakugan active for a long period of time it could cost 1 chakra point to keep it active for some where around half of the full activation to the length of the full activation, i.e. 2 reborn Hyuuga, initial activation cost 2 chakra for 20 turns, after 20 turns 1 more chakra is lost and the Byakugan is extened for another 10-20 turns. And of course upon the user reaching 0 chakra the Byakugan would be immediately deactivated similiar to the Magneyko Sharingan.