Indy-
If you stretch your torso, you'll find that the foot tends to line up with the rib cage. But if you allow too much play through your abs and lower back, that won't happen.

A forward rhumba walk is like the feather? Not sure about that. That's sort of like saying a forward (low) waltz stride is like a forward samba stride.

is this latin or modern? I would guess latin from the desriptions but i'm not big on technique so i don't know for sure....

Assuming you're talking about latin...

I don't know that I would use the term "side lead," although I'm sure you don't mean what that could imply. I am being taught to lead with the side of the ribcage of the foot that's moving...ie, left foot moves forward, the left ribcage moves forward with it (with no turn of the shoulders). A slight turnout is used on the forward walk for balance and to free up the hip, more turn out for a checking action like a break.

Techniques have changed over the ten years you've been competing, including a complete re-write of the ISTD books, but I suspect you may have changed physically even more.

If I can add some thoughts behind my vote;
The front foot would not be turned out for a forward walk when the forward motion is to continue, only for a checked fwd walk to be followed by a backward movement.
Hip action will result in some feeling of a side lead but don't add it deliberately. Just imagine what it would look like to walk along the road using side leads.

Just my opinion of course.