I agree with most of this except that I don't even have fun playing her. Her damage sucks, her teleporter is a worse version of Tracer's recall and the only way to reliably use hacking is on medpacks, as trying to hack mid-fight is suicide and even if you flank a straggler, her audio cues of "Been here all along" and "Here I am" just give away her position before you can even begin hacking. If I'm playing DPS and I see a Sombra, I always switch to Reaper and when her audio cue goes off, more often than not, I find her behind me, ready to eat the dual shotguns. Also as someone who mains Zen on Support, I almost always manage to one up the enemy Sombra.
As someone who's been playing pretty much nothing but Sombra in QP for the last couple of weeks (and is currently #208 Sombra in QP according to overbuff, whatever that means. My handle is Gh0ti) I have to say that the usual way to play her with having a health pack, placing your translocator on it then going in from behind enemy lines is a pretty inefficient way of playing her. You simply have too much downtime between attacks and you won't be outputting enough damage.
I get the most success being above enemies. Stealth in, hack a health pack use her TL to get somewhere hard to get to and fire from there. Once people start going for you, stealth, grab your health pack, TL somewhere else and repeat. You can use stealth defensively this way!
Hacking is extremely situational. Most of the time you have better chances to get a kill just shooting them. You shred through tanks if you get headshots. If you're on a hacked large health pack, Winston can't kill you due to his low DPS.
If you can get behind/above rein, hack him. Hack diva if she over extends. Hack mei if she's being a dick on the payload/capture point. Hack mercy if you catch her coming from spawn to Res. Hack tracer if she's fighting someone else, same with reaper.
That's about it...
In team fights, stick with the team, emp at a good time and focus healers. If you get swamped by enemies, throw your TL and stealth while tl-ing. Then get back to it!
Edit: even so I still only have about 47% win rate with her. I do not dare take her into comp, mostly because of people's rage.