You can hide any field by adding style="display:none" to the table row.
<tr id="trDescription" runat="server" style="display:none">
Be careful tho, if you hide a required field, the field will still be required but the user won't be able to see it, and then wont be able to submit the form.
For the memory, that would be a little more challenging, you would have to add a label to change it to 'Memory (GB)'. But, vCAC will still display the memory in MB, and set the VM to MB's, so I'm not sure how you would achive that.