I'll just say, Shadowjack, that since TMs don't have access to initiative boosters unless a mage casts a spell on them, they take (potentially quite addicting) combat drugs, or hamstring their power with ware, then being in AR/VR and hacking things is probably the best contribution they can make to combat. Sure, if they submerge a couple times and choose the right echoes, they can grab an echo that gives them extra IPs in the meat, but that's a LONG way down the road.
Mutual Signal Range is not required. Routing is an option.
However, these guys should have their PAN slaved to their commlinks, and their commlinks should have decent security. You cannot directly hack into a slaved device, though you can spoof it. To hack it you have to hack the master node. If the enemy is running a centralized tacnet, the master node is probably gonna be a freaking fortress.
You still have to be subscribed to a node within signal range of the node you want to hack, RHat, and be able to find that node in the first place. Also, you don't slave the PAN to the commlink. The PAN is run through the commlink. If you mean that they should be slaving the gun to the PAN, then yes, you're absolutely correct, which is why it is almost always easier to hack the PAN than it is the gun itself.
This is separate from the issues of a tacnet. In a centralized tacnet, the PAN itself is not slaved to the tacnet, but the tacnet is run out of the centralized node. The individual PANs of the tacnet members can still be hacked on their own. Of course, if a hacker gets into one of those PANs, they can then use the tacnet connection as a way into the central node, which they would have to then hack in order to compromise the tacnet proper.
I think the hacking cyberware/guns thing is kind of contrived, myself. Who the heck would leave a weapon's wireless turned on when they know it can be hacked? Same thing for 'ware like wired reflexes. Maybe if turning wireless off wasn't so simple, or skinlinks weren't so cheap, this Ghost In The Shell-type hacking would make more logical sense. But the way the rules are now, the only people with wireless turned on should be gangers like emsquared said, or people with a complicated PAN setup that can't really be hacked within the relatively short time from of combat.
I've always said that the idea of hacking an implant or gun directly is downright silly. You (or a device you're subscribed to) need to be within 3m of someone's cyberware to hack it. That is NOT subtle. What happens, unless someone is blatantly disregarding the rules, is that your PAN gets hacked, and they play with things from there, since all those devices are subscribed to your PAN. What this means is that practicing even basic matrix security can keep you from being an easy target.
But let's just be perfectly honest here. Just like it is theoretically possible to rob Fort Knox, it is possible to hack any system, no matter how secure. All you need is time, a bit of luck, and good enough programs. It is the 'time' thing that makes even a rating 3 Firewall and Rating 3 Analyze and Encrypt programs enough generally to keep you from being hacked long enough to get through combat. That Rating 3 Firewall can come from one of a couple stock operating systems in the core book, and even if you don't get them as part of a package, the Analyze and Encrypt programs together would only run 300 nuyen. Compared to the cost of your ware, that's a pittance. Remember, the secret to not getting robbed isn't to have an impenetrable fortress, it is to make it inconvenient enough that they will likely get caught before they can get in and get the goods, while another guy down the road is a much softer target. Which is why, barring sammies who don't know how to secure their PAN, it is simpler usually to hack the car nearby and run over the sammy.
