Paralysis does not prevent state change, but they'll be more likely to switch to gaseous/ethereal for ease of movement. Freeze is something that hasn't been ruled on in ages and is best to check with your ref, but most would say it doesn't prevent state change, though if you manage to freeze the area around an ethereal or gaseous ghost it would prevent them from going solid. Though if they're ethereal they can just phase through the ice.
As for Psychic/Dark... it's possible to get any typechange, but basically you'd be trading your heart and soul away for it, even with the double Bug weakness.
Haha, I see. Well in this case I'm fighting a Haunter and the trainer is Celebi so ahaha no luck for me! :P Does paralysis or freeze prevent form changes though :O
Also, do you remember if anyone has done a psychic/dar type change? I should get a Psychic/Dark Abra because I need the dark, and psychic. That means a looooootta drawbacks with Abra's lol huge movepool so I sort of need reference. Or is Psychic/Dark one of those "Water/Dragon most likely not happening" type combos?
If your only typespam options are physical, then yeah. But if you have special options, it's best to use a weak physical move going first so they switch to ethereal and then smack them with a special move for the ethereal bonus. Ghosts are all about state changes and fighting them is all about trying to force changes against them if you can.
...a smart Ghost trainer won't let you do that, though, but for most newbie fights it's fairly easy.
What do you mean? Do you mean like I should try to force a Pokemon to go solid with first order, then smack them with some good-typespam that would otherwise not work on a ethereal pokemon?
As for dealing with Ghosts... it really depends on the Ghost you're dealing with. Every one works differently. But trying to make their state changing work against them is usually your best bet.
So I don't know how to deal with ghosts. I believe my squad gets ran over by ghosts. So how do I anti-ghost? Like nothing on my squad knows Snarl or something and I have a grand total of 0 dark types. I'm thinking of dropping one to get a type-changed Dark.