Is it safe to say that centrifugal force and low pressure holds a hurricane together?

Answer 1

In approximate terms, yes. It's called cyclostrophic flow: the pressure gradient force provides the centripetal acceleration to maintain circular motion. (pressure gradient force balancing centrifugal force)

Give or take...

*************
Side note....
*************
The coriolis effect certainly dictates the *direction* of circulation (clockwise in the southern hemisphere, counterclockwise in the northern hemisphere) thus the lack of tropical cyclone formation near the equator.

However the apparent acceleration we attribute to the 'Coriolis Force' plays an insignificant role in determining the equilibrium trajectories of air parcels near a hurricane's core. The distances involved are simply too small (10-100km) - the distance from the surface to the earth's axis changes very little on these scales in the tropics.

Answer 2

It is safe to say that, but I don't think it is correct. The Coriolis force seems to be a significant factor considering that hurricanes within 10° of the equator are very rare. The closest ones in the Atlantic basin were Hurricane #2 of 1933 & Ivan of 2004 - hurricanes between 9° & 10°:

http://weather.unisys.com/hurricane/atlantic/1933/2/track.gif
http://weather.unisys.com/hurricane/atlantic/1933/2/track.dat

http://weather.unisys.com/hurricane/atlantic/2004H/IVAN/track.gif
http://weather.unisys.com/hurricane/atlantic/2004H/IVAN/track.dat

There have been tropical disturbances & storms nearer to the equator, but none within 5° in that basin.

The Pacific basin is different. Tropical cyclones within 10° are not so rare but are within 5°. Here are the closest noteworthy ones:

Typhoon #18 of 1970 strengthened from a tropical storm to a super typhoon between 4° & 5°:

http://weather.unisys.com/hurricane/w_pacific/1970/18/track.gif
http://weather.unisys.com/hurricane/w_pacific/1970/18/track.dat

Typhoon #23 strengthen from a tropical storm well below 10° to a super typhoon at about 12°. Notice though how much it strengthened heading northward (Coriolis force increasing):

http://weather.unisys.com/hurricane/w_pacific/1975/23/track.gif
http://weather.unisys.com/hurricane/w_pacific/1975/23/track.dat

Typhoon #32 of 2001 was classfied as a marginal typhoon at only 1.5°:

http://weather.unisys.com/hurricane/w_pacific/2001/32/track.gif
http://weather.unisys.com/hurricane/w_pacific/2001/32/track.dat

Keep in mind though that is the best that can be found in about 155 seasons in the Atlantic and 60 seasons in the Pacific.