Form field usability issues

At work we have a small external consultancy which don't appear to have much UX/usability experience. For example, their primary approach so far to responsive design has been to have a mobile breakpoint for font sizes (usually expressed in px, to boot) for heading tags, and nothing else. Even text scaling is a foreign concept to them.

We are going to release a new forms system, and they've submitted mockups of what they envision for the form look and feel. Besides the obviously faulty approaches of using placeholder text as labels, floating the label above the form when a user clicks in it, etc., their least poor mockup has each field with the label floated to appear above and inside the field boundary.

With this approach, padding is used to slide the actually enterable portion of the field down. The field boundary in this particular case is a non-gray color and with rounded corners as well. The net visual impact is of a visual bounded region with no visible field inside of it, and a label inside the top.

For dropdowns, there is however at least a visual cue that there's a field there: the down arrow. Still, where a user would expect to see field boundaries, there are none.

I'm a little concerned at this and not sure how to raise my concerns. A/B testing of this before a full release isn't possible currently, or I'd go there. Politically, my boss's boss loves these consultants, so it'd be dicey to simply express concerns without something to back them up.

I see a lot of studies and blogging about rounded vs. square corners, with studies showing that rounded corners can be more inviting and square corners draw more attention. But here, the concern I have over rounded corners is that, without any other visual cue that "here is a field", the rounded corners and the label inside and at the top directly communicates, "This is NOT a field but an empty region". Is there research or other support for this?