For a student studying Chinese as a second language, is there any practical difference between the radicals 匚 and 匸?
For the ordinary practical purposes of reading and writing there is no distinction, even when Chinese is used as a first language.
In some fonts the distinction is only visible in the radicals themselves (匚 and 匸), and not when they appear as ...
Sort of in a rush here so just some hints. First, I'd say the suggestion that 'their pinyin is different, so they must be kept apart' is, well, not wrong and not right. Neither of the two box/enclosure characters is used by itself in the modern language, so the situation never arises. There are also artificial radicals that were never used by themselves and ...
It's a bit complicated.
The first question: is there a (ideally known) finite number of components/radicals?
Yes, the number of radicals is finite. (214 radicals in the traditional Chinese characters, around 301 radicals in simplified Chinese characters), and you can find them here:
The second question: could they be ...