Joker (DX01), Batman (DX12), Two-Face (MMS81), Superman (MMS200) & Zod (MMS216) - Man of Steel, Rocket & Groot (MMS254), Don Corleone (MMS91), Lt. Aldo Raine (MMS118) & Captain America (MMS281).
1. None of these figures has rubber, leather/pleather right? I didn't find any complaints about them. Does anyone know about any problems with them?
Batman wears Full Rubber Suit. Superman uses vinyl/rubber like suit similar to other Superman, some have minor pleather materials like Belt but small items are easier to be replaced/repair.
Predator Classic (MMS 162) and Predator (MMS 090)
2. Have rubber dreads and neck piece. Any problem with them ? I found no complaints about these.
Should be OK unless heat were stucked inside the box causing the rubbers to melt.
Bane (MMS183), Blade (MMS113), T-800 (MMS117), Wolverine (MMS103) & Ezio Auditore (VGM12) - Assassins Creed
3. Have leather/pleather clothes. Any problem with those ?
Hot Toys uses better Pleather materials, but i have the Resident Evil Sheva which uses Pleather Boots, it's still ok but i notice small chips around the belt of the boots which are thinner than normal pleathers. If you apply leather protector or gummypledge or clear rubber coat it may prolong the pleathers. But these figures are pleather heavy, if you really like them keep them, if not sell them.
Superman Christopher Reeve (MMS152), T-800 (MMS117), Wolverine (MMS103) & Bane (MMS183)
4. Have the "rubber" (I believe it's vinyl) upper body and neck. Are they also problematic ?
Depends. Older HT had issues with rubber muscle body, but it doesn't happen to everyone for newer bodies like pleather issue everyones getting. I'm guessing you need to keep it in proper humid/temperature controlled environment, not too dry or wet, not too hot or cold, also dust free. For Superman you shouldn't worry since it's covered in suit. Not sure Wolverine has rubber body.
Sorry for all the questions and thanks for any information.