Regarding BP vs Karmagen, it actually works out very well for technos. While CF's aren't as good a deal, everything else is. I did a comparison character post a while ago, and since you're making a first-time TM, you may want to
look at it for ideas.Threading is a valid specialization for Software; the FAQ clears this up. The book's examples aren't a comprehensive list, and players can make up their own. Gm can still disapprove of it, but, well, they can do that for anything they don't like.
Around my parts, the Martial Arts/Skinlink->resonance trodes/blackout combination is known as The Vulcan Mind-Melding martial artist. Its pretty effective, but there's a few things you're going to need for it to work.
You're going to want the Macro echo, so you can initiate the black ic attack as part of the same action as establishing the touch link. Keep in mind that since you can thread program options, the Psychotropic option is incredibly viable for instant temporary brainwashing. The clinch maneuver can be used to get close enough to touch someone, until they spend an action to try and break the hold. All you need to initiate it is a melee attack, so it combos very nicely with Riposte: by parrying it and hitting back you can set someone up for a resonance-trode based attack on your next action. This is where Macro also comes back to be super nasty: immediate actions are still complex actions, which means your Macro works with it, so you can, say.... full defense AND do something on the internet at the same time. Same thing with Finishing Move.
The downside and MAJOR drawback is...... its a little expensive to use Macro in cyber combat: you need the mesh reality echo, which has the multiprocessing prerequisite. Mesh reality, however, DOES let you fight in the meat space and the cyberspace at the same time, but at a penalty. You can compensate for this penalty in the meat with a Tacnet, and by threading/sprite assisting your combat complex forms to a higher rating for more dice on the cyber level.
Its definitely DOABLE. But you're looking at a minimum of five echoes before you can -really- own with it. And that doesn't even account for getting extra passes to be generally combat-effective.(IP drugs actually work fairly well for this)