You mention a gate enable - is that to enable the '541?
If this is the case, what happens to the control lines on the lcd when the buffer is not enabled? You may require pulldowns and/or pullups

You are right LCD signal lines are connected to '541 buffer. Do I really need pull-up resistors across the lcd signal lines.

Also if a keypad is involved, do you have diodes to isolate the keypad?
For keypad isolation I am using another '541. Although the data lines to the two '541s i.e. LCD 541 and keypad 541 is same but enable lines are separate. Do I really need diodes for keypad isolation even when I have a buffer for this purpose.

Regards,
Prahlad Purohit