But I either don't agree with or don't understand your second issue. It seems that there are two possible problems here:

1. You're concerned about the setting's consistency.
2. You feel that the existance of this power is unfair to Pure Mortals.

Now, just because something's on this list doesn't mean anyone has to use it. I personally I like the idea of technomancy, so I might give Noob Security Systems a try. While I understand that it's out of place in the default Dresden game, I feel that it'll be useful to enough games that it's worth putting on the list.

Partially both.   How does it bypass the passive hexing rules?  I tend to play Pure mortals, so there's likely a bias there.  Technology is pretty much the one "edge" pure mortals have.  The setting (as it's written in the rules and books) also points quite strongly to technology and magic being very seperate.

You may certinly see differently, and want to have technomancers in your game (I Admit to loving the concept a bit myself) so I can see it's inclusion on a list of "possible powers" such as this.

I actually play one of two characters in a game (Twins) where one of them is tech gifted, and the other magically gifted.  My character is constantly trying to both codify the "hexing effect" and circumvent it / protect against it, as well as trying to duplicate magical effects using technology.  The brother (played by a friend) is jealous of "tech boom" and is constantly trying to duplicate technology using magic.  neverminding the fun with the dichotomy.. the inter charater roleplay is Hysterical. 
For me.. giving mages access to technology takes away one of their major disadvantages, and reduces the value of a "pure mortal" in many games (plus it squashes my entire concept)

Have you thought about what said character would likely do to a "threat"?  is he going to eliminate them?  handcuff them?  You  might look for a stunt that helps you "deal" with them.  The other question is if he's a Fist user, why have your guns so high?  Or if he's a gun user.. why no stunts for that as well?

I personally tend to  run a much smaller fate pool.  I can always bring up one of my "interesting" aspects to get some during a game, so I can use them during a challenge.  8 floating seems like a boatload of potential stunts that could be alot more useful than a pile of fate in some circumstances.

  As to the chracter being one dimensional... yes  it does seem like that.  But both the examples you listed are equally one trick ponies.  With any character, there's a balance between being a focused professional, and a jack of all trades.  How's your party set up?  how easily can you as a player trust them to cover your weakspots?  Are you  one of the only character focused on combat?  or one of 5?