Fiduciary commissioners shall have power to preside over all meetings of creditors; to preside over all examinations of the assignor or trustee; to allow and disallow all claims presented to them for determination; to administer oaths to witnesses; to issue subpoenas for the attendance of any person for examination; to examine accounts filed by trustees hereunder, to hear and determine any objections thereto, and to surcharge any trustee for any moneys improperly expended or for which the trustee shall have failed to account; to authorize the business of the assignor to be conducted for limited periods by the trustee if necessary in the best interests of the estate; to reopen estates whenever it appears that they have been closed before being fully administered; to authorize a trustee to bring an action, which he is hereby empowered to maintain, against any person who has received, taken, or in any manner interfered with the estate, property or effects of the debtor, in fraud of his creditors, and which might have been avoided by a creditor of the assignor, and the trustee may recover the property so transferred or its value; to require or allow any inventory or schedule filed to be corrected or amended, and require and compel from time to time supplemental inventories or schedules to be made and filed; to determine the excess of the claims of secured creditors over and above the value of the securities held by them; to require the trustee to render and file the accounts and reports herein provided for; to authorize and approve the payment of costs, expenses, fees and commissions; to declare dividends; to discharge the trustee and his surety after the trustee has properly completed the performance of his duties; to authorize the appointment of an attorney for the trustee if necessary in the best interests of the estate.