Real SINs, Not happy with them as presented. Options

[Redjack]

I'm not happy with SR5 SINs are presented. I think the fluff is cool. I think taxes are kinda wonky as presented and finally, I think the rules (as presented) simply do not justify the costs.

There are four types of SINs: National, Criminal, Corporate Limited, & Corporate Born

Items for discussion:
Spam: National SINs list higher rates of spam as a negative, but provide no in game effects. I think 1-2 additional points of noise equates fluff to rules well.
Social modifiers: Criminal and Corporate SINs both allude to negative social modifiers and/or prejudice. I think that both suspicious(-1)/violent(-3) as well as prejudice (-2) can possibly apply and stack.
Taxes: The idea that the corporations can always find you and extract their tax seems silly; what is the point of "being in the shadows" then? That said, if your lifestyle exceeds your taxable income, then the taxman should come calling. Also, the variable rates seem to not make sense, especially since the most karma expensive SIN has one of the lowest tax rates (doubly confounding since tax rate in the only true game affecting negative impact defined).
Records on File: Quite simply put, in the world of the SR5 matrix, a SIN seems that it should equate to the SR4 Records on File negative quality.
Fake SINs: Following on the heals of the previous point, when your fake SIN is checked, it also seems that sometimes a conflict with a real SIN should be located. This could equate to a dp and/or limit modifier to the checking device. End results could be reduction of fake SIN rating, burning of a fake SIN, SIN reported as stolen, and/or criminal charges related to the fake SIN that could possibly end with the real SIN being converted to a criminal SIN.
Karma Cost: I alluded to this above. To me, the SIN costs simply do not seem to be justified across the various SINs. For example: In game terms a Corporate Limited & Corporate Born SIN both seem to be the same except the tax rate... and the one with the higher tax rate yields a lower karma award.

As usual, I seek your thoughts about how you do or would play them, and that this be a conversation rather than an argument. ergo: In any given person plays with an option or definition, no matter how much you personally cannot imagine playing with it, that option is not "unplayable" because someone is obviously playing with it.

Thanks!