Can I in principle replace any preposition by -n?

Question

I wanted to ask for clarification in this matter for a long time. I think I read somewhere that any preposition can be replaced by -n, but I can't find that source again. What I can find, however, is

1. "The preposition je can replace any other preposition and remain grammatically correct, albeit more ambiguous." [Wiktionary] (although, of course, "Ĝenerale oni evitu je, se pli bona alternativo ekzistas." [PMEG]),

2. "Instead of je the accusative without a preposition may be used." [Rule 14].

I know this would probably not render a very good style, but my question is one of principle: Can I chain these two rules to obtain "any preposition can be replaced by the accusative without a preposition and remain grammatically correct"? Or better still, is such claim quoted anywhere directly?

NB. The whole text of Rule 14 is:

Every preposition has a definite and permanent meaning, but if we have to use a preposition and the direct meaning doesn't tell us what preposition we should take, then we use the preposition je, which has no independent meaning. Instead of je the accusative without a preposition may be used.

One thing that could break my logic would be if the second part only applied if je was obtained via the first part (i.e., if there was no other suitable preposition). But I don't find it clear from the wording whether that is the case, and also (judging by situations like this), who am I to tell?

Answer 1

The preposition "je" should only be used if one of the more precise prepositions doesn't apply to a particular relationship. In practice, the most common use is with time ("je la naŭa horo matene") and with a few other forms like "Mi tenos vin je la brako". While replacing any other preposition with "je" will leave a grammatically correct structure, there's no reason to do that if one of the other prepositions is appropriate.

The Fundamento only explicitly permits replacing "je" with the accusative, but in usage that has been extended to some other prepositions. For some reason today one often hears "you can use the accusative instead of any preposition", which is incorrect. Consider these sentences:

La kato estas sur la tablo. La kato estas la tablon. (ne) Mi manĝas en la hospitalo. Mi manĝas la hospitalon. (ne) La birdo flugas super la arbo. La birdo flugas la arbon. (ne) Mi venis de Aŭstralio. Mi venis Aŭstralion. (ne)

Note that in a construction like

Mi vojaĝos al Parizo --> Mi vojaĝos Parizon

that is actually the use of the accusative to show motion towards, not a use of the accusative to replace the preposition "al".