Hi arnodaub,
About the title, you can go to Customize >Advanced layouts > Archive content.
To fix the layout issue in the sub-categories, you can add the following CSS code to the Customize > Custom CSS:
.grid > .portfolio .item-list[data-cols="2"] > article,
.grid > .portfolio .item-list[data-cols="3"] > article,
.grid > .portfolio .item-list[data-cols="4"] > article,
.grid > .portfolio .item-list[data-cols="5"] > article,
.grid > .portfolio .item-list[data-cols="6"] > article { padding: 25px; }
NOTE: I have helped you configure the option and add Css code.