Why do you want 'pollinating vines'? All plants produce flowers, even if they are't showy. All need pollination unless self-pollinating by wind/disturbance. Vines for partial/full shade are few. Especially if you want to attract pollinators. Not many plants want to reproduce when they are in the shade.
Evergreen clematis performs well in shade, smells wonderful but one needs to have a place where it can go nuts without needing to be restrained. Otherwise it can get quite thick and unruly up close. Akebia does ok in partial shade but better in light.
And clay soil is a great soil. I miss my clay soils...amazing. The only way to IMPROVE ANY soil type is to add decomposed organic matter. Clay makes great plant beds if you double dig and fluff the soil with a spade. NEVER EVER USE a rototiller with heavy clay soils. Makes concrete.
What are you thinking to use to improve your soil? What do you mean by hardness? There is NOTHING I would ever consider using other than DECOMPOSED organic matter that you only have to dump ON TOP of the soil to work. Clay soil is tiny, tiny, flat rocks. If there is any moisture at all and the soil is ROTATED, churned the flat surfaces are electrostatically enhanced and will stick together to make brick/concrete. Concrete is made from clay, water, gravel, gypsum, lime and ROTATION or agitation.
By piling DECOMPOSED organic matter on top, the soil organisms, micro and macro...come up to EAT decomposed organicc matter, tunnel back into your soil profile, poop it out and this is what it takes to make ANY type of soil better. There is NOTHING else to improve your soil!! Add more information/pictures and we can help you do less yet do better.
For cats, you need to avoid any type of LILY!! Daylilly, Calla lily, Iris...these are attractive to cats and will kill them.