No.
Yes they did and they acquired more when they merged with Continental Airlines.
The primary users of 737's are Southwest Airlines Continental Airlines Ryanair Alaska Airlines
Boeing 757-200
United Airlines currently has 24 Boeing 747-400 in service.
Southwest Airlines currently only operate Boeing 737 airplanes. There are several different versions of this airplane though, so the seat count can vary.
Qantas are the only airline that fly the 747 400er
In 1968 I flew into Vietnam on a Continental brand new Boeing 707. The bird with the "golden tail"
All Nippolian airlines has Boeing 787-8.
The term Boeing Business jet refers to their modified model of the Boeing 737 jet. Boeing upgraded these jets and made them bigger to accomodate more passengers and to have more interior space. Most airlines around the world either have or are currently using these jets.
Two. Both are Philippine-registered. In addition, PAL also flew two -200s leased from Republic Airlines.
There are many airlines that primarily use Boeing 757 planes. These airlines include Delta Airlines, United Airlines, American Airlines and UPS Airlines.
Southwest airlines only has Boeing 737s. Nothing else.