around 60 to 70 % N1 on the glide full flaps is normal

reverse operations aren't accelerate. for two reasons
1) you are suposed to flare the airplane idle (this mean reduce the thrust to flight idle at the very end of the flare)
2) as soon your airplane nose gear will touch the ground the idle value will drop to ground idle (20% N1 instead of 40%n1 in flight)

unlock of the reverse is impossible when the airplane is in flight mode (for most of airliners)

in clean config, a airliner would easily track a 3 degrees glide slope in idle and the speed would be very hig
can check the numbers in the AOM I have here (747-dc10-737) but I think it's out of the subject