You might find it better to model two solid tubes in one partbody and then use the shell command. This would also help if you had to come back and edit the model later.
As far as I know you can't delete the material parameter but you can hide it.
Click on formula (f{x}) move down the list until to see PARTBODY\MATERIAL then right click, select hide.
With a volume and a known weight you should be able to make a custom materials database based on supplier parts instead of just the materials.
The only problem with this method is that the COG might not always be correct.
First make your new sheet (sheet 8)
Then cut and paste sheet 3 to 7 starting with sheet 3, which will now become sheet 9 and so on.
Now use sheet properties to rename each sheet.
Use the rectangular pattern and set it 1" then use the more tab and offset 1" in the direction you want.
You should now see the orginal hole and 3 ghost holes, all you have to do now is disable the holes you don't want by clicking the little dot in the middle of each hole.
Jackk: all our parts and sub assemblies are on local coordinates and only the top level assembly is on aircraft coordinates. It’s company policy not to use constraints so all parts are positioned using snap and fix. The job is made easier by publishing geometry at the part and assembly level. If...