The grey’d tasks are your external links. Easiest way to remove tasks is to filter the tasks. You can filter the view by the column External Task equal to or not equal to Yes. Ther is also a Cross Project Linking” section in the Advanced tab of the options dialog box to show external tasks/predecessors.
You can format the external tasks (change it from grey to black for instance) by changing the Text Styles (format/text styles) and bar styles (Format/Format/Bar Styles).
I honestly didn’t know the answer to your baseline question (it’s been a while) so I did some testing and it appears that the external tasks are baselined (I didn’t think that would happen so good news). Hope all this helps.