Cut-Throat - It is VERY thematic for me and ALSO a one shot kill for most solo enemies. The fact that it ignores armor makes killing lone armored soldiers pure gold. It also works on humanoids, so getting Mutants from Stealth is just a bonus. I have a feeling i will use this a lot in Expedition, saw a lot of humanoids and tribals in the trailers.
Electronics - i wanted to focus on poisons (again theme), because i love bear traps combined with Opportunist, but as i said, it seems i can buy anything i want without crafting for now...
The damage i deal now is pretty huge, when i get ripped it will go sky high.
Interloper - i wanted something that will ensure my Cutthroat goes off and so that i can be more mobile when going through an enemy camp (Also theme). I considered dropping it, but it seems to go really well with Cut-throat, and to set up some traps. I am thinking of getting Trap Expert so that i can fast plant traps while in stealth. The whole idea is that i start combat under my terms without needing to run around killing everyone, let them come to me (or my traps )
Expose Weakness- i thought i would need something against armor that would combine good with Opportunist and Taser. But again, i did not expect to be flooded with cash..
Cutthroat has a bunch of issues. It requires either incap or stealth, it costs 25 AP, it doesn't work on anything that isn't humanoid, long CD unless specced, it requires specific positioning, and there are also enemies immune to stun. That's a lot of drawbacks to take out only one enemy type at the cost of a feat when there's so many feats a knife can benefit from universally upfront. The AP cost alone is a huge problem. You can eventually reach 5 AP swings and with a proper build you will more often than not spend less AP just using auto attack to kill an enemy than you would using Cutthroat. For theme I get it though
Electronics-As you said you can buy most of the traps.
Interloper- I've just never had a scenario where I couldn't do what I needed to do without interloper but by all means go for it. Just gave my two cents on the feat. I would suggest quick tinkering over Trap expert. You can lay your traps down instantly so you can do it right in front of someones face and then scoot away without anyone noticing. That won't work with trap expert
Expose weakness- Shock knives and energy knives make it irrelevant in my eyes but it's not like its a terrible waste or anything.