hehehe I think you have mistaken the "loft" tool for the "project curve onto surface" tool. (or am I too tired to write any sense here )

About projecting curves onto surfaces;

-You "usually" pick the curve and shift klick the surface in one of the ORTHOGONICAL views, but you may find it neccessary sometimes to use this tool in the perspective view (a little tricky to aim correctly but it is ok).

When using this tool you may get an additional set of projected curves, if you project onto a volume and not a "simple/plain" surface.

I'm not sure why you got your curves at the wrong place.


About the trim tools:

-To be able to trim a surface you must have a projected curve which "would" produce an ENCLOSED part on that surface, meaning that it cannot be an open projection-curve (unless it is really a really small gap, in which you can use a default value in the options or set your own value, which makes maya disregard small gaps, thus giving you a proper trim-result. Otherwise you get an error (I think).

-You can pick (carefully) the projection-curve and go into component-mode and select a cv for movement along the surface, which may close any gap you have. I usually draw curves that overshoots the surface, so I don't experience any gaps later on.

Did you know...
That you can untrim a surface via the nurbs menu item. This calls back the original surface before ANY trimming. The good thing is that you still keep your projection curves, they do not get lost if you do an un-trim action.

Did you know...
That if you (for some reason) have projected several curves onto a surface, and if you discard only one part by a single selection, then (If I am remembering correctly) you loose the other projected curves. Correct me if I'm wrong here guys.

Did you know...
That by keeping your history button ON, you can manipulate the produces trimmed surface, by selecting (carefully, it can be tricky to select sometimes) the projected curve, which still can be found on the trimmed surface, and... make a trimmed hole become bigger or smaller (for example).


About the lofting tool:

-You can pick several "objects" to produce a lofted surface, either by picking two or more curves (sequencially),
OR a curve and an isoparm...
OR a curve and a trimmed edge
OR an isoparm and a trimmed edge
OR any combination of the above (I think)

-Keeping your history on can be pretty helpful, because you can then move the "constitutive" parts of the lofted surface (curves, trimmed edge or isoparm) and alter the shape automaticly.