Relation Managers: Attach or Create a New Tag

Error throwed while deleting tags which are attached to any product and vice versa.

To delete Product or Tag without Error

// ProductResource
// ---
Tables\Actions\DeleteBulkAction::make()->before(
		function (Collection $records) {
				$records->each(function (Product $record){
						$record->tags()->detach();
				});
		}
),
// ---
//--------------------------------------------------------------------------


// EditProduct
// ---
Actions\DeleteAction::make()->before(
		function (Product $record){
				$record->tags()->detach();
		}
),
// ---
//--------------------------------------------------------------------------


// TagResource
// ---
->bulkActions([
		Tables\Actions\DeleteBulkAction::make()->before(
				function (Collection $records) {
						$records->each(function (Tag $record){
								$record->products()->detach();
						});
				}
		),
]);
// ---


//--------------------------------------------------------------------------
// EditTag
// ---
Actions\DeleteAction::make()->before(
		function (Tag $record){
				$record->products()->detach();
		}
),
// ---


//--------------------------------------------------------------------------
// TagsRelationManager
// ---
->actions([
		Tables\Actions\DetachAction::make(),
		Tables\Actions\EditAction::make(),
		Tables\Actions\DeleteAction::make()->before(
				function (Tag $record){
						$record->products()->detach();
				}
		),
])
->bulkActions([
		Tables\Actions\DeleteBulkAction::make()->before(
				function (Collection $records) {
						$records->each(function (Tag $record){
								$record->products()->detach();
						});
				}
		),
]);
// ---

Can we elaborate on this lesson with slightly more advanced example likie one with Project, Member and Responsibility.

Member BelongsToMany Projects with Pivot Responsibility. Is this at all possible to attach new Member to Project with multiselected responsibilities in fillamentPHP?

how attach user id who creating post for example we have posts table and we want to each post belongs to userId who creat it? we have user_id in posts table.

why the relationManager only appers in edit form, not also in create from?