Yeah, it is a bit of a dilemma - on one side its so exciting to experience raising goldfish fry for the first time, on the other hand there is just no space in the house to put them. Before you decide what you would do with fry, maybe its time to look around in your area for a koi or goldfish club, or even a aquarium society, and I am quite sure once you located a club, that there will always be members interested in taking some fish off your hands, and you can be sure that they know the basics of goldfish keeping.
There is also the option of finding a pet store which would be willing to take some, but in that case you never know if the potential owners of your fish will ever take care of them properly. Friends and family are also an option for future goldfish keepers.
Also be prepared that it takes quite some work to keep those little buggers happy and healthy. There should be a pinned topic about basic fry rearing pinned on top of this section. They need a lot more feeding than adults, preferably live food, or fry food as a second choice. To plan ahead it would be great to have a sponge filter already hanging around in one of your other tanks, so its cycled by the time the parents decide to breed.
All in all, it is a great experience, and I am always excited when this time of year approaches, where spawns are most likely.
As to the parents eating the eggs if you don't take them out - thats a big YES!! No matter how much you fed them, they'll always looking for some extras, and a couple of hundred eggs sure sound like a great meal to them. If you have a planted tank where fry could hide out from the parents, there is a slim chance that some might make it, but don't count on it.
You are right about the hand spawning - it is very risky, and should only be tried by experienced breeders who know what they are doing. It needs to be done gently, otherwise damage to the internal organs can easily be done.
Oh, yes, tropicals breed like there is no tomorrow, and they are indeed easier. Its also nice to see that you see the finished product already in hand with the life bearers, while with goldfish fry, or any egg layers, it takes time until you see a little mini goldfish developing.