Bet amount certainly plays a big part. This is what philosopheer means when he talks about "the mathematics of the game". Bet amount is part of that mathematical part; it's basically a signal of your confidence against the current size of the pot. This is why, when you do reading, many strategies will talk about bet amounts as multipliers of the current pot.

Timing can be informative, but it's actually weaker online than in person. In person, you know whether the person is physically present, and can generally gauge when they're paying attention also. Online, taking a long time could simply mean that they're not paying attention. (I've watched streams on Twitch of pro players working multiple tables online.)