Not quite. I use my kanji knowledge to deduce what the kanji compounds in a Japanese text mean if necessary. Also, Japanese shares many kanji compounds with Chinese, so I could “read” those in Chinese if I wanted. Finally, the way Japanese combines words and ideas is quite similar to what Chinese does (e.g. when two verbs come together and form a compound verb), so figuring the underlying logic out isn’t that hard if I know the kanji involved.
I made this point because it seemed the OP was discussing ‘understanding’, so I figured I would just mention the fact that I understand what it’s like to have a tendency to use kanji to deduce what’s going on both since they help divide the sentence into words and remove the need to guess which word with a particular reading is being used based on context. Quite naturally, I don’t know the reading of every single kanji I come across, even if I know it in Chinese, but it’s the same even for Japanese learners: not everyone knows all the readings for particular kanji and when to use them e.g. 雑 is usually ざつ, but in 雑巾, it’s ぞう. I’m sorry if I’m coming off as overly defensive, but I feel as though you take issue with the fact that I dare to use my Chinese knowledge to help me with Japanese, or that you feel a need to make me concede that kanji knowledge is insufficient, whereas I made no such claim and was just trying to show the OP that I feel I understand his/her situation. I was also just pointing out why I might have been comfortable using a textbook that contained lots of kanji from the get-go. If you were just asking what it’s like out of curiosity, then I’m sorry for misinterpreting what you said.
I see in your next post that you feel it’s dangerous to ‘over-emphasise’ kanji. Fair enough: there’s no point learning kanji in isolation, and it’s silly to learn, say, 3 readings per kanji and to then roll dice to guess how they combine in compounds. The compounds themselves are words in their own right, and they need to be learnt as blocks for the sake of communication and in order to know the right readings. That doesn’t mean it’s wrong to break them down into individual kanji in order to figure out what’s being referred to, even if in Japanese, it’s often the word that came first, with the kanji being attached to it just because it’s contextually appropriate. Also, again, I tend to find that Japanese words combine very similarly to Chinese words, so it’s often true that the word containing the kanji (e.g. a verb stem) will combine with other Japanese words the same way the kanji itself might in Chinese.
By the way, please don’t assume that being a Chinese speaker and stating that I know most of the kanji I see means I’m promoting learning kanji in isolation since Chinese is the language for which kanji were made and that there’s usually a one-to-one correspondence between ‘words’ (units of meaning) and kanji in Chinese. (That last statement isn’t clearly true because there are lots of homophones with similar meanings in Chinese too, even if most things defined by a set of sounds and a particular meaning can only be written one way.) In Chinese, kanji readings change based on meaning and context, and it’s not impossible to know a word or phrase without knowing how to write it: the experiences of speakers of Chinese dialects prove it since they’re fluent without necessarily knowing how to write what they’re saying since Mandarin is the standard dialect used mostly frequently in education now. I dare say a Chinese speaker’s approach is very appropriate for tackling kanji in Japanese: kanji should be learnt because they provide meaning or refer clearly to a particular word, but the learner should also be aware that readings and meaning can change based on context, and knowing words is often more helpful than individual kanji. (I don’t know if you’ve seen this before, but any pair of Chinese speakers discussing which kanji is being used among a set of homophones will almost definitely reach for the most common compounds containing the kanji concerned. Modern Mandarin relies on two-kanji compounds (each of which you might quite rightly call a ‘word’) a lot, and it’s not uncommon to explain the meaning of individual kanji using the words that contain them. Chinese speakers don’t learn kanji in isolation either.)
Finally, to answer your question directly: I can’t pronounce all of the Japanese words represented by the kanji I know. Definitely not. I wouldn’t dare to claim otherwise because I don’t know all the combinations possible in Japanese. 投与, for instance, is a combination that exists in Japanese but not in Chinese, even though it’s made of relatively simple kanji that I know and frequently use in Chinese. I’m sure there are other such compounds. However, provided I know the kanji involved, I can guess most of the readings for compounds correctly because they’re often on’yomi. Also, knowing how readings in Mandarin translate to readings in Japanese means I can identify words I hear and link them to the kanji being used based on context. I don’t need to see the kanji, though I’ll check the dictionary afterwards to be sure I was right. Such intuition isn’t limited to on’yomi either: kun’yomi linked to a particular kanji are often similar across words, like how 上 is うえ in isolation but becomes うわ in words like 上回る. You know the two are related based not only on meaning, but also based on the fact that most of the old W row in Japanese dropped the W sound at some point e.g. ゑ → え, and that the H row has undergone a lot of pronunciation changes (because the sounds above used to be written as うへ and うは, but the logic behind the sound changes is probably what led to dropping the W sounds). Similar patterns can be found in pairs like 終わる and 終える, meaning that we can get an inkling of the correct readings for words linked by the same kanji (e.g. by anticipating a vowel change), even if knowing the kanji is not necessary for acquiring this knowledge and simply acts as a means of mental organisation.
Ultimately, my point is that kanji-specific knowledge can be useful, including knowing readings of individual kanji, even if kanji shouldn’t be studied in isolation and it’s much more fun to learn words and phrases in context while adding the nuances they express to one’s knowledge of the kanji they contain. That’s how Chinese speakers learn kanji in Chinese too, excluding kanji that are so obscure the dictionary is the only way out.
