The Parade route and the
Cover-Up are just 2
of the things the mob needed to Control.
The Feds would run the cover-up for them. The Feds couldn't afford to have the word get out that the Mob just whacked a sitting president. The Federal government would have unfilled positions all over the country in a matter of weeks and political elections would have no candidates.
God, it was the usual parade route. Oliver Stone got that wrong, among almost everything else.
The route was dictated by where Kennedy needed to go to give his speech.
There was no coverup. The basic facts of the case were known within days, and haven't changed.