Taking a crack at these:

1) If by '3d Cursor' you mean the yellow ball with red, green and blue offshoots, then in the main SUMA viewer, go to View -> Cross Hair to toggle it's viewing on/off.

2) To turn off the large outline box, click on F5 while the mouse cursor is over the main SUMA viewer.

3) To view the ROIs, you can load in the 'volume' in the following way:
$ suma -tract TRACT_FILE_000.niml.tract -vol ROI_FILE'[0]'
(I put the explicit brick index on the volume because I assume you want the ROI network associated with your tracts; if you only ran tracking on one network, then you don't need that; if you are looking at TRACT_FILE_001.niml.tract, then use -vol ROI_FILE'[1]', etc.

Volumes by default are viewed as slices to start. To view the volume ROIs as filled-in bricks, open the Object Controller from View; right click on a volume slice, and in the Object Viewer controls for that volume, beneath the Slice Controls on the left is a 'Volume Rendering Controls' minibox-- click the checkbox next to the 'v' there (-> for volume viewing). You can adjust the smoothness of the surfaces by adjusting the value in the Ns box there.

And for a nice colormap for ROIs, go to the right side of that same Controller, beneath the color bar, and right click on the 'Cmp' (=colormap), and select for example ygbrp256 or some other one of those -- it's discretized for integers rather than smooth, so each ROI will be a very different color and not just, e.g., a whiter shade of pale or something.

--pt