It's actually pretty straightforward.I can't imagine what a nightmare Chinese transcriptions are. Isn't an "X" much more like a "Sh" and a "Q" almost like a "K"?
k/g/h - Pretty much matches English, except the last one is Russian kh, Scottish ch, etc.
z/c/s - dz/ts/s. It makes more sense when you know that ts-like sounds are often spelled with a z (German, Italian) or c (Slavic languages) (or both, in the history of Spanish).
zh/ch/sh - Like the above, but with the tongue tip pulled back in the mouth to around the place where the roof of your mouth goes smooth. They end up sounding like a "harder" (lower-pitched) English j/ch/sh.
j/q/x - These are the "soft" versions of all three of the previous, like how English and Romance languages vary c and g based on the next vowel, or how Japanese ti turns into chi. These are pronounced by placing the tip of the tongue behind the lower teeth and raising the body of the tongue to make a sound similar to a higher-pitched j/ch/sh. They only exist before orthographic <i> and <u> (in which case the <u> is pronounced like French u, German ü, etc).
So you have a low-pitched series pronounced with the tongue tip (zh/ch/sh) and a high-pitched series pronounced with the tongue body (j/q/x). Slavic and Indian languages often have the same.
The problem with Latin is the limited number of letters; j/q/x are are the three that you can count on having unexpected pronunciations. Though these are not without precedent, j we know from English, q is used for a similar sound in Albanian, and x is similar to Medieval Spanish and Portuguese, and by extension Mesoamerican Latin alphabets and Vietnamese (though thanks to sound shifts, Vietnamese x and s basically switched pronunciations ).
EDIT: Woops, missed that it rolled over to another page!
I'm pretty sure things like "credit card" are compound words.
Set phrases tend to act as single words, and eventually undergo sound changes, phonological reduction, etc as if they were single words, no matter what their component words are. This is how we get "goodbye" from the saying "God be with you." I'd also guess this is how "I could care less" came about - the saying itself has been divorced from the meaning of its constituent words, and it just so happens that the first reduction has been something that when you analyze it as individual words, means the opposite of what was intended.What about word combinations that can't be split in half? Like vice versa, or deus ex machina?