

Walter doesn't actually lie to Peter as much as he lies around him
Something I noticed on the rewatch is that Walter will often avoid answering Peter rather than actually lying to him.
Peter asks a direct question, Walter starts talking about something completely unrelated, gets distracted, makes some weird comment about food or a cow, whatever.
The first time I watched it I mostly took it as Walter being Walter.
Knowing what he's hiding makes a lot of those scenes feel different. He's not always trying to convince Peter of a false story. A lot of the time he's just trying to get through the conversation without saying the one thing he knows he can't tell him.
It's a really good way of showing that Walter is carrying something enormous without having him constantly look guilty.
The thing about T-Bag that gets overlooked is how quickly he reads people
T-Bag is obviously a complete piece of shit, but he's rarely stupid.
What makes him dangerous in Fox River isn't really physical strength. He figures out pretty quickly what people want, what they're scared of, and who they think they can trust.
The Michael thing is probably the best example. He doesn't understand Michael's entire plan, but he knows almost immediately that Michael is hiding something and that there's value in staying close to him.
It's one of those characters where being charismatic and being absolutely fucking awful somehow coexist.