Topology problem - disconnected vertices.

I have a toplogy problem, and I would appreciate any tips or pointers in solving it.

Background overview - I am building various extrusion/loft patterns over regular surface UV's. These are generated from surface split and loft operations, which are then exported as mesh.

The problem occurs when the resulting set of surfaces is converted/welded to a single mesh. Topology is far from being ideally linked. As you see in screenshot(s), there are plenty of vertices that are not linked fully within the mesh.

Is there a way to retopologize or generate a mesh with linked vertices?

My goal is to be able to export to other software - like ZBrush. I am not looking at perfect topology flow, I am just hoping to get something that can be subdivided without gaps.

Second screenshot demonstrates the subdivision problems - with gaps showing up around vertices that sit on the edges but do not link.

Is there any way of solving this? I'll be happy to use any tool, including anything outside grasshopper/rhino toolset.