What you may not appreciate is that some RC beliefs, while incredible to outsiders, nevertheless are logically inseparable from other beliefs that are shared with other Christians; once abandoned, other cracks form, and it all falls down, including parts which are widely accepted as true.

Internal consistency is a virtue to be sure, although differences in degree of internal consistency between Christian sub-sects all of whose beliefs are based on multiple irrational and/or self-contradictory premises do not mean a great deal to me personally.

RC is, as you say, the religion which "tried hardest to rationalise" all its beliefs, depending on the absolute minimum of non-rational arguments (i.e., from sacred scripture or human authority). It does this with a vocabulary which, I admit, is extremely challenging to the uninitiated. (Aristotelian/Thomistic logic and hylemorphism.) Nonetheless, within that philosophical system, it is quite consistent. It's like picking up a book on string theory -- you ain't gonna "get it" on the first pass (nor the second pass, in all likelihood.)

As a philosopher I think that it's good intellectual exercise to get to grips with bad arguments like those the Catholic church use. However there's no truth in those arguments to "get", and there are other forms of intellectual exercise which might well be more beneficial for the general LW readership.

(Sorta off-topic) I was not aware that people doubted the existence of the founder of Buddhism. If he did not exist, could a reasonable religion be attributed to him? <scratches head> :-)

A religion could be the most rational and consistent of religions if its sole departure from reality was a fictional founder. Christianity, for example, has a fictional founder (the Biblical Jesus never existed according to the available evidence nor anyone substantially like him) but has lots of other departures from reality as well.