Lost Fastship functionality

Rhino can import offsets in a number of formats. Points can be imported from a .txt file, for example. Here is an excerpt from the Rhino Help file:
To open or import a point file:
1. From the File menu, click Open or Import.
2. In the dialog box, in the Files of type box, select Points File (*.asc; *.csv; *.txt; *.xyz).
3. In the File name box, type a name for the file.
4. Click Open.
5. In the Points File Import Options dialog box, select the delimiter character and specify whether to create a point cloud object from the file.
6. Click OK.
Note: Point files must be in the form: x,y,z with no additional heading information at the top. The characters can be separated with a variety of characters and can be surrounded by quotation marks.

Also, remember that Rhino can also import DXF and IGES files with polylines. While it currently does not have a function to fit a candidate surface to a set of points, it does have the ability to "loft" surfaces through curve networks as well as to evaluate the deviation between a set of points and a surface.
FastShip’s fit function, and the freeze/thaw capability, don’t yet exist in Orca3D, but are on the development list.

Regarding your other questions:

-How to insert a row or column in the net?
Use Rhino’s insertcontrolpoint function (Edit/Control Points/Insert Control Point)

-How to connect nodes of two different surfaces?
Use the Point Osnap. Once control points are on top of one another, you can select all of them with a fence selection.

-Live update of sections is rather slow..
This is very dependent upon your tolerance settings in Rhino. Also, right now Orca updates the sections on the entire surface, rather than just that portion of the surface that is affected by the control point(s) being moved. We hope to optimize it in a future release.

-No possibility to create construction geometry
You can use Rhino’s standard drawing tools to create any type of geometry that you need (perhaps on a separate layer). With the Onsnap, control points will snap to this geometry. . In Rhino, you can create a much broader spectrum of geometry, (points, lines circles, curves, surfaces, volumes, point clouds) and any of these can be used as reference geometry via a much more extensive object snap tool. Sometimes the process is slightly different. For example, to draw a “construction” line in Rhino that extends beyond the two points that you use to define the line, use the polyline command, and turn the Helpers option on. Click on the two points, and you’ll see a “helper” line extending to infinity. Click a third time on this helper line where you want the construction line to end.

-Missing metapoles
This is on the development list. In the meantime, you may find that cage editing suffices for some of your needs.

-No possibility to refine the sections
When you put down a control point, Rhino automatically refines the sections to the tolerance settings in File/Properties/Units, which saves a step over the FastShip process. If the sections aren’t refined enough, adjust the tolerance settings, select the surface(s), and right-click on the Sections icon to refresh the sections.

-The standard color scheme from Rhino is not as convenient as the colors used in Fastship
This is a matter of personal preference, of course, but the colors of the control net may be adjusted in the Orca Properties dialog (orcaproperties or Orca3D/Properties).

-Are there plans to get this all back?
In general, many of the FastShip features you refer to have much more capable counterparts in Rhino. It is mostly a matter of getting use to them.