Well first off, I'll cover Form Fit and PPP systems. Think about it logically. Why wouldn't you wear them if YOU were a runner. In my experience if the thing is a no brainer, it's only an issue if it wouldn't be a no brainer in rl. Cops wear their vests, corpers carry their doc wagon biomonitors, and runners wear their form-fit. This has been standard since form-fit was first introduced to the game world in my experience.
As for stick-n-shock, I have a hard time believing that most corps wouldn't standard issue non-conductive their armor. Mostly because of the fact that tasers, stun batons, etc are easier to legally get and what your average angry wageslave would have access to in a hurry. Afterall, standard security is not meant to stand up to Runner teams, they're meant to stand up to gangers, disgruntled employees, etc.
Seeing as we have the technology now to make something similar to these rounds for shotguns, I don't feel its unrealistic for them to be in every caliber in 2072. That said, a much better rule would be heavy pistol or larger rather than only shotguns in my opinion just to make it realistic.
My personal houserule that my group uses is this:
Stick-n-Shock attacks gain no extra DV from narrow bursts.
Cyberlimbs are useful for once in the history of the game. I don't mind it at all. If a player lays an AGI 1 character in front of me, I'd laugh because there will be cases where he will use his all over AGI rather than just his attack arms.
Now, I do have a problem with cyber-diabetes/leperocy/munchkinism where the character has two cyberfeet and two cyberhands full of armor. That said, unless its a prewritten adventure that I'm not supposed to change to much (like missions), I don't have a problem taking on high armor runners.
On an off topic note, modern tasers are not effective against actual armor, but it does take some very very thick clothing to one hundred percent always stop them. During the winters I wear a leather duster with a thick hoodie underneath, layered over my tee shirt and thermal shirt. During my unlucky college years I was tasered a couple times and only once did my clothing actually stop a dart (although the second dart quickly nullified that thought at the time).
If you're wanting to change tasers to be more realistic, then I suggest using the same rules for injection darts.