Basically, when a fixture is deleted, all related information (group assignment, cues & times, palettes) is removed along with unassigning the DMX address - whilst parking a fixture only removes the DMX assignment, and retains everything else.
Further, an interesting information might be that copying a fixture transfers all the additional information (palettes, cues, times) to the copied one.
The best way for you depends from your programming habits. One way would be to setup a minimalistic default show, with only one fixture/channel per position. Then, instead of patching, you copy the fixtures, and assign DMX addresses (Repatch). Backdraw of this approach: you don't retain changes (e.g. in timing) from one day/venue to another.
Another approach: always work with the same - finally maximum - show. I reckon you basically know the venues you'll come to. So: patch e.g. 4 or 6 dimmers for each position you might need. Use groups! Give them useful names! Layout the fixtures in the fixture window according to the setup! Then, when you start the day, check each group if all contained channels behave correctly.
Finally, whilst the overview of the patch is better in 'View'-'Fixture Patch', Parking/Repatching is more easily done (to my mind) in the patch menu. You might use the printout tool at
www.avolites.de/test/d4z to printout the current patchlist.
Best, Sebastian