1- Eh... Yes....ish? We don't consider that particularly noteworthy given the Cuckoos at the same event and Teen Jean when she had just arrived in the present (barely a telepath) have also been able to read his mind.
2- We need to wait and see how the event plays out before we can fully evaluate the Brood feat. Suffice to say it's hard to pinpoint what's happening when and where across the 2 books and it's caused some debate.
3. Mastermind had been locked into a machine running 7 illusions at once for days. While getting out is impressive for her.....its ultimately more of an anti feat then anything else.
1- Exodus as stated has the problem of his faith amp. We try our best not to factor in any outside power sources or other things that would change from situation to situation.
In the Rachel example for instance he states that his powers are based in belief and that he has never believed in something more then his cause at that moment. That would mean that, even though he's shown incredible multitasking in the past his performance against her there is outside his usual levels.
Similarly his 2 confrontations with Xavier.
During their first meeting in Bloodties Exodus is able to withstand a full power psibolt from Xavier while maintaining his mindcontrol over Jean Grey and several others as well as crushing a city with his forcefield.
During their next meeting in X-Men Legacy, he was in possession of all of Xavier's memories and was using them against him. Xavier would eventually overpower him and threaten to turn his powers off completely if he continued the battle.
Factoring that in we had to consider Legacy and Messiah complex to be as close to normal for him as possible since there's no statements or outliers in either appearance that would make you question his abilities.
Sinister however doesn't have anything to question. While there's no doubt that Exodus is stronger then him in raw power, Sinister himself scales directly to the raw power of Emma Frost (via a stalemate against Emma Frost) who isn't exactly weak. The fact that Sinister has given Emma trouble on multiple occasions and yet Exodus himself admits that he's unable to use his TK while battling her (something he was even able to do against Xavier under the same writer) it points to the fact that Sinister is likely more skilled then Exodus. A point further proven by the fact that Exodus himself considers Sinister one of the most skilled telepaths on the planet.
Long story short, Sinister generally comes across as more skilled in mental manipulation and where his power levels are pretty consistent Exodus has massive outliers and other performances marred by his own admitted amp.
2- Both of them would be considered about as powerful as Jean Grey and Professor X give or take. With Legion easily pushing beyond that given his statements of having "multiple Omega level- telepathic personalities".
3- The Cuckoos are hard to judge individually. Generally by statements Sophie > Esme > Mindee > Celeste> Phoebe. And by feats Esme > Sophie > Celeste > Mindee > Phoebe.
There's various statements about like "whoever wears the black/white outfit is the dominant mind of the day" that we could consider. But Esme is the only Cuckoo who's stated and shown to be able to beat and over power other Cuckoos at their current levels.
4- Any and all telepathy feats for Maddie were considered. Barring things like sleep spells or control magic that she doesn't have to actively maintain.
5- Quentin isn't easily compared to other psychics. His greatest outliers are so far above his norm that he's almost a different character. However the best interpretation of him currently is that his raw power was enough to keep up with Emma Frost in restraining the Phoenix Force for a short time and while he himself isn't compared to her, the Pale Girl (who's power Xavier compared to Jean Grey) was unable to see through his illusion for hours.
The best most reasonable outcome is that he is close to Emma or Sinister in raw power at his ABSOLUTE best (a great deal less on most days) but that his real strength is the complexity of his mind and use of his powers rather then pure raw power.
Slightly longer answer? She's being treated really well and with alot of respect as a psychic, but in terms of telepathy she hasn't really done much on her own worth mentioning.
Apoc being so high when his feats are mostly "defended against" or some contextual stuff with Hulk for example is depressing
Jean having a seizure off his tp, cross dimensional tp and stuff like the hulk exchange were shaky but comparable to the mastermind girls.
The defense stuff just makes it harder to get around when your trying to argue them above him...but it didn't help him get above, say, Selene who has worst defense and similarly contextual showings.
Koays's comments