Breadcrumbs and categories enhancement

I think that breadcrumbs are quite important for a website (usability wise) that's why I would like to make them work a little better in this theme. To be more specific this is what I would like to do:

Now, by default, when a user is reading an article the breadcrumbs structure is this:
Home >> Article title
When a user is in a category the breadcrumbs structure is this:
Home >> Category title

I would like to make them like this, when a user is reading an article:
Home >> Category title >> Article title

Also I would like that specific category to be highlighted in some way so that the user sees clearly where he is both in the header (top menu - category links) and, in my case, in the left sidebar were I list all content categories.

Right now, when a user clicks on a category, the title of that category, in the left sidebar, will show a small green check mark notifying the user that he is in that category but the top menu doesn't change.

I would like to correct these two things: breadcrumbs structure to show the categories titles when a user is reading an article and the category to be highlighted both in the left sidebar and the header top menu.

How can I solve these two problems?