Hi everyone.... I'm totally new to everything Fondant-related....
Would you believe it if I told you that I 'discovered' fondant less than a week ago?
So far I'v made and brought only whip cream cakes.... As far as I know, we don't get fondant cakes in here.... Anyway, coming to my queries....
I researched a bit and I tried making rolled fondant which didn't come out well... I'm planning on making MMF with homemade marshmallows (where I live, marshmallows don't come cheap!)
In the marshmallow making videos I saw, they left the marshmallow-'batter' to set for a few hours... and in MMF tutorials, they melt the marshmallows and then kneaded it... I was wondering that if I skip the part where I have to leave the marshmallow to set and directly knead the 'batter', will it work?
and from what I'v read and seen, MMF is kinda dough-like.... but what will it's texture be after I cover the cake with it? Will it dry out and become hard or will it remain soft? Do i have to refrigerate the cake after covering it? Can i cover a cake with MMF after icing it with whip cream? Can I use fondant accents on a whip cream cake? I read somewhere that the accents will 'bleed'... So could I coat my whip cream cake with piping gel and then top it off with fondant accents? Come to think about it, can I even coat a whip cream cake with piping gel..?!?
Any help will be appreciated.... Thank you...

I think the reason that you leave the marshmallows and the other ingredients to sit out after you melt them is that they're so hot they'll burn your hands if you try to knead the mixture right away. Let it sit till it's cool enough to handle, then knead away. After you finish kneading you WILL need to let it set for at least six hours, or better yet overnight, tightly wrapped in several layers of plastic wrap, not in the fridge. The fondant has to "ripen" for awhile before you can use it. I don't think it would do well at all on top of whipped cream because there is no way you can get whipped cream hard enough to keep it from being squishy while you put the fondant on it, and fondant will not go on smoothly on top of something that moves around. The whipped cream will probably also be moist enough to melt your fondant after a couple of hours. The same goes for fondant accents on whipped cream, sorry to say, and even if you could ice your whipped cream with piping gel (which sounds like a LOT of work and might not even be possible without mixing the two together), piping gel has the same problem as whipped cream: it's liquid enough to melt your fondant after a few hours, and strongly colored fondant will bleed into it, as well. You'd be better off putting your fondant on top of buttercream, because you can harden buttercream up in the fridge for a little bit before you put the fondant on. In my opinion, the best thing you can put under fondant is ganache (there are recipes in the recipe sections here on CC ). Good luck!

........planning on making MMF with homemade marshmallows (where I live, marshmallows don't come cheap........

I think this will really mess up the recipe. There is a BIG difference between homemade MM and commercial. Homemade MM is usually much softer to begin with so it will give a different consistency to the MMF.

.......... MMF is kinda dough-like.... but what will it's texture be after I cover the cake with it? Will it dry out and become hard or will it remain soft?.......

It develops a sort of hard finish but basically remains soft. It does NOT get hard like gumpaste or royal icing

....... refrigerate the cake after covering it?..........

Not a good idea unless you use a filling that must be refrigerated.

Good points, kakeladi, I kind of glossed over those, but I agree.

Oh.... Thanks a lot....

If marshmallows aren't cheap in your neck of the woods, you may want to try Michelle Foster's homemade fondant (in recipes). It's melt in your mouth yummy, nice to work with and may be cheaper for you to make.
AND if you like the texture of whipped cream icing, try Whipped cream buttercream (also in recipe section). It does well under fondant and you don't have to worry about refrigerating.
Good luck!

Here are good directions for MMF:

http://sugarsweetcakesandtreats.blogspot.com/2010/09/recipe-marshmallow-fondant-mmf.html

And if you read around that blog, you might find a lot of your answers, and recipes for other buttercreams.

There are very good recipes for fondant out there, including Michelle Foster's homemade fondant and Toba Garrett's fondant.