I guess my main concern is the gear hanging up on extension. The nose gear
is
no problem as the doors are linked to the nose gear. The mains drag on the
doors as they open. With no hydaulic pressure, the doors slam down. Would
increasing the low pressure help?

Bill,

 

You said : With no hydaulic pressure, the doors slam down

 

Does that mean that the dump valve was opened with the pump motor breaker pulled?  If so, it is easy to see that the door springs had enough strength so that the actuators were not starved for fluid even though the nose gear was pushed out by its gas spring.  When the pump is powered, it is trying to deliver juice to all the gear actuators and the door actuators are delayed (deprived).  This may be inherent in the way the gear system is plumbed.  Perhaps stronger springs in the door actuators could overcome this problem.