Front panel shut line ...can it be adjusted?

Can you use the word "easily" when dealing with coachwork?

The 328 SPC indicates the brackets for that front lower section have a lot of adjustability possible (and adding/subtracting shims as needed/wherever needed is often done, too):

https://www.ferrariparts.co.uk/diagram/ferrari/328-gtb-gts-(1985)/101-body-shell-outer-elements-(not-for-us-and-sa-version)

Not sure that you can make the gap even all the way across looking at your photos, but you should be able to make the gap at the left side and the right side more equal (even if the gap at the middle is something slightly different). Has it had some prior coachwork repair in that area? Seems like the uneven gap variation is more in the upper sheet metal piece (with the Cavallino emblem) than in the placement of the front bumper. Can't think it left the factory like that...

 

See this thread here about your car..
https://www.ferrarichat.com/forum/threads/328-lower-panel-valance-question.658314/