That's a good character. Quite excellent for a first time! There's no safety handrails in Shadowrun's classless chargen system, but you avoided falling into any traps that first timers so often fall victim to.
The good: You want to have a nice, big dice pool in your primary schtick. For deckers, that's Cracking and Engineering. You have more than 12 dice in each there, that's what I consider the goal. True minmaxers will want 16+, but I don't think that's truly necessary. But with your specializations, you're in that neighborhood, so you're certainly good on your primary schtick.
You avoided use of the Impaired Attribute neg quality. I absolutely hate that cheese, so I commend you for not using it. (but, if maximum munchkin is your goal, you're totally missing out on a bunch of karma)
Skills: Kind of the inevitable downside to overspecializing in one schtick is being one dimensional. You do an admirable job of avoiding the worst of that. Excellent use of attribute points and resources to end up with mostly viable dice pools even at low skill rank values. I'd quibble a little bit about putting firearms at 3 instead of perception or stealth, but it's small potatoes. Really it depends on the rest of your team, so if I were you I wouldn't change it just because someone else says they'd do that one thing a little different.
Specializations: this is where I have some bad news to share. Cracking is for illegal matrix actions, and Electronics is for legal matrix actions. Specializing in illegal/legal is akin to taking a specialization in Firearms of "guns that fire bullets". No sane GM is going to let that fly. You'll want to establish with your GM what the Hacking and Computer specializations do and don't cover, since he'll be telling you rather than you telling him. Per the description of "Hacking actions" on page 182, I advise you to prepare for your GM to rule that Cracking (Hacking) only covers Brute Force and Backdoor Entry. If your GM is familiar with 5e, he might instead say that Hacking specialization covers the matrix actions that the 5e Hacking skill covered in 5e. Namely: Crack File, Backdoor Entry (in place of Hack on the Fly), Spoof Command. Ditto for the Computer specialization for electronics. "All legal matrix actions" is overly broad. It basically covers everything the skill covers, rather than being a specialization in a subset of things. Your GM would be nuts to agree to that interpretation, but if you have a nutty GM, congrats
Same thing for "Pistols" for Firearms, but to a lesser degree. Per the most recent errata, the "book specializations" are the same as the categories listed in the gear section. That is, the specializations are: Tasers, Hold-Outs, Light Pistols, Machine Pistols, Heavy Pistols, SMGs, Shotguns, Rifles, Machine Guns. Of course, if your GM will let you combine two categories into one specialization, more power to you.
Q&A:
1) I think I covered my views above!
2) Built Tough seems like an awful expensive luxury for a non-combatant. I think you're well rounded... wouldn't be worth becoming more one dimensional for a bigger CM. MAYBE if your one dimension was physical combat, but that's not even your schtick so in no way would it be worth giving anything you have up to gain Built Tough 3.
3) I'd keep the Bone Density, even without any skill in Close Combat. Soak dice are very important. You may be a noncombatant, but that won't stop NPCs from shooting at you.
4) Aaaaaaah... I didn't realize that those specializations are post-chargen until just now. Heh, it helps explain why your character looks so good. It's including 25 more karma than chargen gives!
Still, I wouldn't change it. GM credit/rebuild opportunities are what they are, and no point in NOT using that karma to your best advantage! EDIT: I Have to concur with Hobbes about Athletics. Maybe instead of 2 of those specializations take Athletics and Close Combat.
5) Hard to go wrong with the Predator... it's a truth across every edition of Shadowrun. As a minor point: the Praetor is a SMG, not a machine pistol. (though, it looks like you're going off the German language rules, so if the German CRB calls it a machine pistol, never mind me...)
6) mandatory equipment every runner should have:
Fake SIN with fake licenses for every (L) coded bit of gear you don't plan on hiding inside your body. And since cyberware scanners are a thing, I'd recommend getting permits even for that...
A cheap commlink you can afford to use once and throw away
Contacts and earbuds to cover vision and hearing augmentations you didn't get via cyber/bioware
AR-interaction tech (image link+AR gloves, or DNI. Cyberjack satisfies that for your char)
Toolkits for your skills (In your case, you'll want Biotech, Engineering, and Electronics toolkits. Probably also want a First Aid kit, since everyone will be looking at you to be the healer)
Lowlight or Thermographic flashlight (as appropriate to your vision enhancements)
Respirator
Suggestions specific to your character:
Cyberprograms
Lockpick tools
Sequencer
Passkey
Card Reader
