Correct you wont have problems integrating with the vbulletin software itself but no one can say your not going to have hack issues if your running hacks. vbulletin themselves will tell you this.
I can tell you if you want things to display correctly you must set those two config switches on so that the vb
stuff will be called correctly and properly format the review.
Now if you have an issue with the actual quick reply then you need to actually open a support thread on that but my thoughts without even seeing your site is that this would be a hack conflict. For instance if you dont see the quickreply in the quickreply box it is definately a hack causing that. Then again I cant respond further without knowing the exact issue. That is why I said disable your plugins and if things work then you know for sure its a hack issue.