I am not sure what you're expecting a reply to LyDDa. You simply asked if anyone was using 'Stab' with their fades and suggested maybe there should be a discussion about the ability.
What are your impressions with the ability? Should it be adjusted because it's too weak/powerful? Is the timing of the ability not correct? Do you feel it doesn't fit the way a fade is typically played? There are a lot of things you can say about 'Stab', but you don't mention what you dislike, like, or want to change about it. The more information you give in your post, the more likely you will receive an informed response regarding it. I will do my best here though and assume you simply do not like it at all and want it gone, possibly replaced with something unknown.
In my opinion, the largest obstacle for 'Stab' is that it unlocks on Biomass seven (which requires three hives). There are other, stronger abilities and third hive traits that are more worthwhile to prioritize as well as the need to secure more ground with Crags/Shades/Shifts/Whips/Cysts. Aliens do not typically sit on three hives for very long; either they will win shortly after or marines will kill one of the three. So the time a fade will ever have the opportunity to use 'Stab' is minute.
On top of that, the ability requires that you are comfortable enough with the timing of the stab to use it in combat at proper times. Other third hive abilities require less practice and are more intuitive in use. However, there haven't been many proper suggestions for a replacement. The most popular that I've heard is 'Acid Rocket', an ability that Fades had in NS1, but it was ruled out after discussion. If you have a good suggestion, feel free to put your idea out there. Something proper would be: intuitive, fit the role, balanced, and easy to implement.
At the end of the day though, it loops back to the first point; you won't have it for very long. I don't think that 'Stab' in the game the way it currently is, has much impact on the game and changing it to something else may cause imbalance and the payoff isn't there at the moment to worry about it.
If you would like to suggest possible changes to the ability to balance it better (earlier availability, different damage, faster swing, etc.), that would have a higher chance of success in changing it.
Now, on to webs, adrenaline, camouflage, and babblers. This is going to get the same criticism from me. If you want a discussion about something in the game, put your opinion of it out there first as well as what you would like to see adjusted. Simply mentioning an ability or upgrade and saying discuss isn't helpful.
I'm assuming that all of these are being put up because you don't think they're used very often and/or are not worth using comparatively. Let's get babblers out of the way. Babblers will never be strong. I happen to like babblers. I think it's fun for a gorge to give a temporary shield to a skulk at the cost of personal resources. However, in practice, a lot of players complain when it gets used often. It isn't fun or interesting to play against. So that's why they're in the state they are today, used rarely because their effectiveness is about 10% of what it used to be last year. I still use them occasionally as a commander gorge since my resources are unlikely to reach a higher lifeform and it is still a small boost in fights, particularly early engagements.
Now, 'Web' falls in to the same category as the aforementioned 'Stab': it's only on third hive, isn't available often enough to become familiar with use, and isn't initially intuitive. Now, I'm not saying webs are hard to use. They're simple in how they work, but players are not sure where is best to place the webs or when to use them. I would say that overall 'Web' is an underrated and potentially powerful ability. I'd recommend teams use it more to secure escape routes when you push instead of relying solely on bonewalls to save retreating lifeforms.
I'm going to go ahead and talk about 'Adrenaline' and 'Camouflage' briefly since I've gone on a bit of a rant here, but abilities are easier to balance in my opinion than upgrades. Abilities apply to one lifeform and their timing is manageable through Biomass. Upgrades, on the other hand, apply to all lifeforms and because of this have to be simple (extra armor, extra speed, less sound, etc.). There are limited ways you can upgrade all lifeforms without making it too complex. 'Camouflage' is most useful early in the game, especially if your team stays on one or two veils instead of rushing to three. Later in the rounds it becomes less used, but I think it has reached a good spot since it was decoupled from 'Silence'.
'Adrenaline' is just not very good and may need to be adjusted. As far as I've observed, Shift is already the least used hive and 'Celerity' is used almost exclusively. The problem is I don't think simply increasing the rate of energy regeneration would make 'Adrenaline' more widely used. As it stands now it is easy enough to manage your energy through practice that you will never need it. Previously you would to see Fades with it prior to 'Metabolize', but now it isn't as useful. Unfortunately, making it harder to manage energy on lifeforms would make aliens overall weaker and, let's be honest, it would be less fun to play. Another solution is to change the ability to something else completely, but that creates more problems than it solves, at least initially.