I boxed in red what I think is the maximum working pressure for each model...Am I correct?
I do not see anything.
For example, the VTS 250D has a working pressure of 5-125psig. So, in the event that one wants to replace the LPG the best choice is to go with one with a maximum 200psi... Correct?
This is correct to some degree; you can replace the low pressure gauge with one that is lower than the maximum working pressure (see below).
I've noticed that some people use 100 psi or recommend to use this gauges...isn't that a risk? What if one accidentaly goes over the 100psi mark...the gauge will break. Right?
Yes, if you go over the 100 PSI mark accidentally, while the regulator itself will be fine (since it was designed to handle that delivery pressure), you will break the low pressure gauge.