Newbie questions

I've just updated to the Pro version. Before that I had some custom CSS code. I took it out before upgrading so I could start clean, but there are some oddities and I don't know if old code didn't get removed? On this page the headings "Facebook Groups" and "Videos" are supposed to be in the same heading format (4) as in the previous link, but I accidentally wiped out the Heading 4 formatting while working in Pro. Now I don't know how to reset it to the default. How can we edit heading fonts, bold etc? From any page, if you hover over Records > Ireland Records ... then the submenu falls off the right side of the screen. Any suggestions how best to handle that? I have my primary menu items in alphabetical order so prefer this item at the far right... However, I've just noticed that in Chrome and Safari my primary menu fits horizontally, while in Firefox (Mac) it wraps and Research ends up on a second line :(