Thank you very much for the helpful advice.
So my transit path will be:
Deplane->Immigration->Baggage Claim->Walk on arrival level TBIT-T4-T5-T6->Check-in
I spare 3:45 for transit, hopefully it's enough for I&C and TSA.
About the walk TBIT-T4-T5-T6, can I make use of connector/tunnels?