Fallout – What are the outcomes of each experimental option in the Vault-Tec Workshop DLC

That seems to be the only difference. Items with a green trim can be picked up, moved, and placed in the settlement, or stored in the workbench for later use (note: it seems you can only store items that you can build yourself from scrap. Some items can be moved/placed and functionally used, but not stored, such as white picket fences). Items with yellow trim are simply for salvaging materials, and their names occasionally imply this, as they are often "ruined" items (ruined house, broken toilet). Yellow items are also not movable in workshop mode, which also supports that they don't have any real use in the settlement.

It seems safe to scrap anything with a yellow outline, with maybe a couple of exceptions. If you scrap a container (such as mailboxes), you might want to make sure it is empty first, or you'll have to retrieve the contents from the workshop inventory later. Or, perhaps, if you wanted to keep any trees that remain upright in the settlement, don't scrap it for wood.

I have limited experience since I'm only on my second playthrough however so far I have observed -

If you join the Minutemen you'll end up allied with the Railroad and will end up destroying the Brotherhood of Steel and the Institute.

Additionally, if you've progressed through the Minutemen missions (upto and including retaking the castle) then during the mission where the Institute attempt to "invite" Wallace to join their Biosciences team it will be the Minutemen that respond to Wallace's distress call (thus giving you the opportunity to talk them out of it). If you haven't joined the Minutemen, the Gunners will turn up to respond to Wallace's call for help. Progressing through the Minutemen story will also result in numerous groups of wandering Minutemen patrolling the wastelands in addition to unlocking artillery.

If you join the Brotherhood of Steel, you'll declare war against the Institute and Railroad while being allied with the Minutemen.

If you join the Railroad you'll be allied with the Minutemen and destroy the Brotherhood of Steel and the Institute.

If you join the Institute you'll be allied with the Minutemen and destroy the Railroad and the Brotherhood of Steel.

After completing the storyline allied with the Institute, groups of synths start showing up all over the commonwealth announcing that the Institute is now in charge - they'll also set up a variety of checkpoints and roam the wastelands killing mutants and raiders. The various companions I used during my playthrough didn't mind that I had sided with the Institute however I expect that Deacon and Danse might (since you destroyed their factions).

Regardless of which choice you make,

"Father" will die, however the cutscene will be different if you aren't allied with the Institute. If you attack the Institute you'll lose that as a fast travel location. Any factions that you wipe out will not be available for missions after the final cutscene.