Why couldn't God be omnipotent and have a physical body? 
 
To me omnipotent= all powerful. 
 
Christ had power over everything, yet he had a physical body. Why would that exclude God the Father from having a physical body? 
 
We definately do accept the book of Revelations.

This derives from the age old question "Can God create a rock that is too heavy for him to lift?" No matter what belief someone has in God, an answer would show weakness, and therfore not omnipotent. A body could never hinder God's work.

Omnipotence (having all power) is evidenced through Christ's victory over death when He was resurrected and took up His body again. We definitely believe that God is omnipotent, but we do not believe that a lack of body shows all power, but rather that a physical body is a part of God's perfect and omnipotent character.  
 
If having a physical body is unfavorable or even hindering to God's power then it would not make much sense that the Son of God would choose to be resurrected with a body of flesh and bone. (See Luke 24) It is important to realize though, that God's body is not like ours. His is perfect, immortal, and glorified. 
 
Essential to God's plan for us is that through Jesus Christ we will all receive a resurrection to be more like unto Christ. (Phillipians 3:20-21) 
 
Hope that helps.