Premiere intuitively does this pretty well…just zoom out a bit so you can see both ends. Also positioning the CTI at one end helps the “Snap to” thingy.
If you see the jitters only on TV (not PC), you may have a field reversal issue. DV is lower field first…check you project settings in FCP and your export settings.
May be time to reinstall Premiere. If you have 3rd party plug-ins, save the “Plug-ins” folder to another location, do a complete ununstall, reinstall and then copy/paste your old Plug-in folder overwriting the installed folder.