speed , unit , menu

I installed LOP on 4 gb usb flash.

1. SPEED

Is there anythingelse I can do to make LOP run faster?

I have done these:

The JavaRE is UNchecked

Memory> Undo> Step is 20

Memory> Graphic Cache> Use for LOP is 128 mb
Memory> Graphic Cache> Memory per object 20 mb

Cache for inserted object> Number of Objects> 20

2. UNIT

For LOP-Writer the Measurement Unit is Millimeter. But, Why the value can not be set to, say, exactly 5 mm ?

3. MENU

The unavilable menu is light green. Can it be changed to other colour, say, dark gray ? Or, is it only on my computer?

Thank you.
DL
.