i agree, you're making rather a big stipulation regarding the future which frankly once you're gone its no longer up to you.
they may not want all this hassle, i realsie its your great grandmas house and means somethign to you - but it might just be bricks and mortar to them.
if you give something to someone you must let them then do whatver they choose - as it is, you are organising THEIR future for them.
and as mentioned - how can you leave a house to all those kids - yet none can sell it? what happens then? they all live in it together? only one family can live it - so who chooses that?
if none want to live there, does it just sit empty?
you are setting these kids up for a future of court dates, arguments and fallings out because of your desire to control the future.
my dad did something like this to us - he bought shops when we were little with the intention of us working in them when we were older - and then eventually taking over- basically he mapped out our future for us, with no thought to what we actually might want to do.
he was furious when only only one of the 3 of us wanted to do that, and still even now sees it as an insult because we didnt abide by his plans
he tried to plan our whole lives and was strangely surprised when we didnt want him too...
the point is he thought he was helping us. he was doing a very generous and thoughtful thing, wanting to be sure that we all had jobs and a business in th efuture and had money - which is a great thing for a dad to do, and i am grateful to him for caring and thinking ahead like that ... but even so, my life is my life, it was not what i wanted to do, and if i dont want to work in a shop for the rest of my life then i cant do it just so as my dad isnt upset.
you may think this is helping them but you may just be causing them trouble, which could have them all falling out over it .. same as unevenly splitting the shares based on the wealth of each one - it may help the poorer ones, but may also breed resentment...particularly if the reason why they are poor is due to their own laziness or whatever.