We have case open for this, working with Brittany.
1. If you are going to remove the Misc Parts field from the Project Summary, your math will be off on the proposal unless you change all of the dtr:Price fields to dtr:ExtendedPrice. In addition to the "main" proposal report, modifications must also be made to the following subreports: Proposal Level2 Items, Proposal Level3 Items, Project Summary Detail. Note: dtr:ExtendedPrice includes both the Misc Parts % AND the Equipment +/- % so making this change may trump your second question since the Equipment Adjustments (regardless of what you rename it) shown in the Project Summary will not add up properly - you will essentially be showing the charge twice, once in the body of report and again in the summary.
2. This
post shows how to modify the Project Summary subreport to change wording for elements.