If you follow the diet strictly, this in all likelihood would prevent any further attack till the surgery. Low fat diet is the best way of prevention of acute gall bladder pain.
The risk of clot is due to inactivity. Since it is done laparoscopically (minimal access surgery), people are inactive just for a day, so chance of clot is low. Walking short walks after the surgery will definitely help and prevent the blood clot.
Please feel free for your follow up questions.
I would be happy to assist you further, if you need any more information.
You are very welcome.
You can have fresh juices, which are the best beverage when one have gallstones. You can eat all kind of fruits, vegetables and freshwater fish. Avoid butter, oil, cream, eggs, cheese, fatty meats and full-fat milk. Here is a link about the diet details;
It is privilege assisting you.