Please some help with the following expressions:
1. He was sentenced in life imprisonment.
2. This is insurance contract will be in effect for (all) your whole life or This is a whole life insurance policy (i.e. it will be terminated only in case of your death).
3. I would like to inform you that your son died on time of duty: My question here is whether I should use: (a) Ya xotel by proinformirovat' or Ya xotel by informirovat'
4. When I end a letter I want to say: Please don't hesitate to ask for any questions you might have. . I don't want a translation, I just want to use the correct russian way. I think that Russians usually use the expression: обратиться с вопросом