Hey Tim!
Yes, this can be changed relatively easy actually, by using the "live-edit" feature (bottom-right corner):

Just follow these steps:
- Activate live-edit
- Expand the context menu of a post
- Click on the "edit"-button next to the text
- Enter the new text in there and save the changes
I think you need admin rights for this if I check in
this FAQ. Let me know if you have issues with it.
As to your second question, if this is a good idea or not: I am not sure. It could be that your users will use it too often for regular support questions, but I have never tried this myself. However my Super users also used to flag content to me via this feature, even if it was not something which needed to be moderated...
I am not sure which role volunteers have on your community. I later had a dedicated topic in a hidden category where my superusers would post links to comments - it is a bit more work for your users, however makes it a bit more managable in my opinion, also because real actual abuse reports will not run a risk of not being checked in time.
One final tip though: Also think about changing or optimizing the text in the actual formular. Should this not be possible via live-edit, then I can provide you with the "codes" to add the new text manually via the back-end.