What is the impact on a transferor if a Sec. 351 exchange involves the assumption of the shareholder’s liabilities by the corporation?

What is the impact on a transferor if a Sec. 351 exchange involves the assumption of the shareholder’s liabilities by the corporation? What conditions need to be met to avoid IRS classification of loans from shareholders as equity (contributions to capital)? What is the tax treatment of losses from worthless stock or securities? What is the tax consequence if an eligible entity elects to change from being treated as a corporation to being treated as a partnership or proprietorship? If losses are suspended as a result of the lack of basis in S corporation stock, do the losses expire when the S election terminates? When does a partner recognize gain on a contribution of property to a partnership? What is the partnership’s basis in property contributed to the partnership by a partner? When is a partnership considered terminated? What are the IRS rules for determining the tax year of a partnership? How are start-up expenses and organization expenses handled for a new partnership?