The text arrows can be turned off in admin > Configuration > Layout Settings > Categories Separator between the Category Name and Count.

These control the subcat prefix and indentation:
Categories Separator between the Category Name and Sub Categories  
Categories SubCategories Indent   

For the arrows on top cats (there should be small arrows just like the All Products link has, which turn to large arrows when selected), apparently your stylesheet has some declaration that overrides the stylesheet_categories_dressing specification. When I add "#categories " to the selectors, they work as designed.
Code:
/* bullet for top categories & links:*/

#categories a.category-top-text, #categories a.category-not-selected,  #categories a.category-subs-selected, #categories a.category-links {
    display: list-item;
    list-style: disc inside url(../images/bullet1.gif);
    }