1. There are a few options to choose from, but I'd go with Daniel Bryan. Batista's out doing his movie thing, I don't see Angle and WWE reaching an agreement before Fast Lane, and I also don't see Sting rushing a return with a bad neck at his age. Bryan has apparently been cleared to compete and WWE was always going to bring him back eventually, there's no better time than right now. Bryan wants to compete, he's able to compete, thus he's the most likely to return before Mania at this point.
2. I would have said Neville, but my opinion has kind of shifted with the injury to Sin Cara. Kalisto has been kept relatively strong when he's in the ring by himself, picking up big wins over Ryback, Kofi, and ADR throughout the last couple of months. It's not impossible to think that Kalisto might get the big rub of going over ADR to win the US title at Wrestlemania with all the injuries that have piled up. He's over with the crowd, can seriously go in the ring, and most importantly, he has momentum heading into the RTW. He and Neville are both in good positions right now to break through to the next level, I just think Kalisto has a better shot at this point.
3. Roman Reigns vs HHH: This will probably be for the title as I can't see Reigns not being involved in the WWEWHC match. Than again, I'm thinking Lesnar has a good shot of winning the Rumble and defending against Reigns while we see Reigns/HHH at Fast Lane. Right now I'll stick with Roman/HHH as it makes the most sense and Lesnar would probably be more useful in another match.
Bray Wyatt vs Brock Lesnar: Hasn't happened before, and I can buy Wyatt possibly winning with his family at his back. Again, this just seems to make sense and would go with Wyatt's strategy of randomly targeting his opponents. Lesnar enters the Rumble, eventually lights go off, and the family comes out to screw Lesnar. I think this is very possible.
Undertaker vs Kevin Owens: I would have liked to put Owens/Lesnar but with the injury to Cena, I think it makes more sense to stick Owens with Taker instead of doing Wyatt/Taker 3 or 2, or whatever match they're on. It also goes hand-in-hand with his "lack of respect for wrestling veterans" gimmick.
That's three fresh and intriguing matches. We finally get the, like, 2 year blow-off from HHH/Reigns, and Owens and Wyatt have the potential to become the stars that WWE desperately needs them to be.