The only catastrophic water pump failures I recall was related to bearing failure on a Crown water pump. Bearings are funny things; unless you get a bad one they tend to run a loong time as long as the seals stay good. To the extent I've seen posts on water pump "failures" it's been the typical fluid leaking. The down side of that is the leak is likely to only show up on the bottom of the inner timing belt cover above the front skid which makes it really hard to find. Bottom line is you pays your money/time and takes your chances. I know some have had the OEM pump start to leak not long after a 100K TB change but others have had no problem. FYI if you do go ahead and do the pump replacement now be sure to use Sir Sam's front half only replacement as that takes care of all the moving parts and avoids the hassle of several very hard to reach bolts.

Your temp readings are a classic tstat failed open symptom. Options:
1. inline tstat in the upper radiator hose. I've participated in that discussion but am not a big fan of the idea. If you do go this route be sure to clamp the inline in the hose up near the OEM tstat outlet so it doesn't migrate to the radiator core intake flange and drill a 1/8" or so hole in the inline tstat skirt if it doesn't already have one. The hole is an old timer's trick to prevent catastrophic overheating if a tstat fails closed but in this case what is does is smooth out the coolant warm up by faking the system into acting like the OEM tstat is bypassing coolant to the block like it should when the engine is cold while properly leaking some coolant to the radiator. Once the inline opens up things act like normal.
2. same as above but use the Meziere WN0072 Inline Thermostat Housing for the install instead of inside the hose. Otherwise same comments as above.
3. OEM tstat replacement. If you go this route be advised the lower back bolt is a challenge due to a hump or some such in the manifold. Use a 1/4" socket and wobble extension to avoid the problem. You cannot drain all the coolant out of the system by gravity but you can do several drain/fill/run engine for 3 minutes and repeat like 3 times with demineralized water to get most all of the old coolant out. Do a final drain, leaving the valve on the top passenger side of the radiator open, fill from the coolant tank on the firewall with ca. 6.6qts of Xerox G-05 or Mopar HOAT antifreeze (coolant system amount is inconsistent in the manuals but I'm pretty sure it's 13.2qts so that fill gives you a 50/50 mix), top off with demineralized water, until fluid comes out of that radiator valve, burp the upper radiator hose, redo top off, close valve, add water to coolant tank to about 3/4" above midline, replace coolant tank cap, do 2-3 drive cycles (cold to operating temp and back) and recheck fluid level (should go to about tank midline as air bleeds out of the system).
4. Kap's modified tstat housing but he is in OZ and way behind on building them.

If you go with options 1, 2, or 4 a 190-195F tstat is best per GDE as that gets engine operating temp into a bit warmer and better combustion range than the OEM tstat which is ca. 180F. I can tell you that my bad OEM tstat cost me ca. 1-2 mpg in town during the cooler months when, running with heat and/or not AC, my temp gauge sat at 3/8ths.

If your water pump fails, the pistons hit the valves. Get the German one from ID. It is OEM quality. How many water pumps last 200K miles?

DOC