limited irrevocable power of attorney on a loan

Hello, on my loan documents there is a document titled limited irrevocable power of attorney stating that I give the mortage co or any officer thereof power to endorse, execute, sign and seal any adjusted document related to the mortgage loan issued. it also states that I grant and convey the attorney in fact full authority to act in any manner necessary including full power to substitute or revoce and ratify every act of the mortgage co. they are offering me a fixed rate for 10 years. however the note did not say fixed. if I sign this documents will they have the power to sell my loan to another co. at a later time? if they do can they give me a loan with different terms? please respond with any advise. thanks

 

thanks for your response. well it says the undersigned borrower does hereby further grant and convey to the attorney in fact full authority to act in any manner necessary or proper to the exercise of the foregoing powers including full power of substitution or revocation and ratify every act os ___ mortgage co. would this give them power to sell my loan to another co and change the term of the loan Isigned with them. any advise would be greatly appreciated