"I read a lot of books."
There are case the words cannot move in the sentence. 'おもしろい' '本を' 読みます。 In this sentence, cannot be grammatically replaced.
'本を' 'よく' 読みます。 'よく' '本を' 読みます。 Each sentence is grammatically correct. But the meanings are different. I did not recommend moving in this case.
'たくさん' 本を' 読みます。 '本を' 'たくさん' 読みます。 Both are okay as sentences of Japanese. I think that it is not a mistake to use 'たくさん本を読みます' instead of '本をたくさん読みます'. I think these meaning are 'almost' equivalent.
I am not a native speaker of English, you know about it because you saw my bad sentences. So I do not know difference between 'I read a lot of books' and 'I read books a lot'. I don't know how much nuance is different.
Sorry maybe I didn't explain myself properly. I know all that. I mean what is the difference between Direct object + wo(o) and Direct object + ha(wa).
Is it similar to Subject + ga and Subject + ha? If so, then is Direct object + wo something we already know and Direct object + ha a new topic or talking generally about that object? Thanks