Its an interesting point of view. But if i accept your premise there is something i dont understand:
If they know you did something (micro or camera) in the first place why they didnt turn it off. If they dont care its the same as giving you access to sensible information.
Well, I have couple of guesses:
Cordia:
With Cordia, MC's monologue "Did she see me at the first night?" is most likely confirming she saw MC sneaking into her office somehow. With her girls rooms, it's not said, so it's left ambiguous (but let's just say she knows, and disapproves in her mind).
And if she knows and turns it off, MC would know something has gone amiss. Given that she picks up on MC being already uncomfortable in their first meeting (when MC first meets Cordia when brought to the Family), it could possibly be that she didn't interfere and just left the MC to his devices to ease him into living with the Family and all.
Now yes, there is chance that sensitive information getting leaked to MC, but with Cordia and Wilfred knowing, I'd assume they'd be able to control what gets discussed or not in the office.
Wilfred:
With Wilfred, while it's not said, I think most of us can probably make an educated guess that he knows about the devices.
So why does he let MC keep the devices on?
Hmmm...... from what I can tell, I think it may have to do with the aspect of Wilfred that is the watcher.
He seems to like to pull on strings behind the scenes, then steps behind to see how things play out (like how he deals with Luna and MC's situation in My name is Luna).
In my eyes it's a bit of flaw of his in which he can't help himself but to act that way (even when he's not actually working officially as a Consigliere).
So when he found out MC has planted the device in Cordia's office, my thought is Wilfred might react like "Oh? Let's see how this turns out." not necessarily for the sake of any test, but for his own sense of amusement.
Following your theory (tell me if im missunderstanding something) the rule is: "If we found you doing something wrong, there will be consequences, if you cant found you then nothing happened" (unless you do something problematic like selling intel to the enemy).
If all of the murder attempts were something they were controlling, and they are allowing your actions because it was a test, a way to develop your skills, part of a plan, or they take a benefit, it makes a lot of sense. But if the murder attempts were real (outside force) and they allow this i really cant see them not caring enough or any benefit at all, but they will know you can have access to intel that it isnt allowed in your rank.
Being found out isn't restricted to just selling intel out to the Family's enemies.
It can also very much apply to Cameras/Audio recorders being found out by any of the girls and just the main Family members (Luna, Gracie, Isabel, Cordia, Antonio, Wilfred) finding out what MC did (without the event and any info leaking to outside the main Family).
That would still have the grave consequences towards the MC from the Family cause there would be that breach of trust, with some (especially with Luna, Isabel, Antonio, who likely won't know the devices exist), and disappointment from others (like Gracie who might have suspicions).
Cordia and Wilfred, even if they were turning a blind eye till then, if MC actually gets caught, will need to act on it.
I think in regards to the assassination attempts (there's only two which would count, first being the car brakes, and the second being the poison, Eiza's I exclude that one since a lot of factors outside of DeLuca's control come into play for that one), I'm more inclined to believe the actual Family didn't know of the assassination attempts.
Cordia always values honor and respect, so no way her moral compass would allow such actions to be taken, even for the sake of testing the MC.
Wilfred, I think he'd be willing to get into much greyer territory than Cordia regarding his actions, but I'm not sure. Even if he's doing it as a test, I'd say he's doing it all without Cordia's permission (basically Wilfred gone rogue).
I'm actually leaning more towards that there could be another traitor/mole.
DeLucas think they quashed the traitor /mole with Trino, but there could have been more than 1 in the Family who might be willing to turn their back on them (Antonio or Wilfred seem to be the most popular choices of fans with the traitor candidates, but I'm not too sure. Seems a bit too obvious to me. Oh well..... guess we'll find out sooner or later how it turns out).
While MC getting sensitive information might be helpful to him (that is if they do decide to intentionally leak it to him) I feel it's a double edged sword.
On one hand, it might help him to better prepare himself, while on the other hand, the info may also put him in much more dangerous position (than when he wasn't aware of the info).
But that's part of the beauty of this game.
It gives both sides for the player to ponder about.