Is there any way to figure the actual odds for the bets on events ("betting" section), or could you provide more info on how are the final odds calculated?
Are the "estimated odds" just a very rough indication of the expected winnings if the prize pool stays the same, or is the bet somehow locked at certain odds. i.e. if I was to place a bet at say the odds of 3.0, can the actual odds drop significantly (say to 1.10) if later on more people bet on the same outcome as I did?
The "estimated odds" are indeed just a rough indication of the expected winnings of the prize pool at that moment. It's subject to change based on how much money is bet on each side after you bet. However, earlier bets are weighted higher than bets that come after you as a way to incentivize earlier betting on a prop, and this plays a factor as well on the payouts.
If a ton of people all pile into the same side of the bet as you, it would dilute the payout for all. The hope is that as the odds change, the increase in odds on the opposite side would incentivize people into that side of the bet to keep the payout in the ballpark of what you were shown. However, the dilution is a possibility. The weighting of the money that comes after you would be less than your bet, so that would have a bit of an offsetting effect, but if a whale came in and bet 10x your bet, you could see materially less on the payout than what was indicated by the calculator when you made your bet.