@awoski All of those sites load fine for me in both Chrome and FIrefox (I don’t have IE). Do you have the most up to date version of both browsers? It sounds like it could be a local issue.
I always recommend checking the load times by using https://tools.pingdom.com/
Here you can test how quickly your site loads by various locations (in addition to the more important “time to first byte”)
I also do not see any issues with the nav bar on any of the browsers. Could you elaborate on exactly what is wrong with the nav bar for you in Firefox? Screenshots would be very helpful.