Does 45-d replacement property identified mean offer accepted for new property?

[Raman Saka]

Hi, I am in the early stages of doing my first 1031 exchange. We are yet to list the property I am replacing, but curious about the 45-d replacement property identified condition. Does that IRS condition mean that I need to have my offers accepted on the replacement properties? OR I can be in the process of doing walk throughs, making offers/counter offers and everything is OK as long as I close in 180 days?

Also has anybody tried to pick up Bank owned properties as replacement properties for 1031 exchange OR the best advice is to keep it simple and straight forward on properties where you can confidently close within the allotted timeframe?

Cheers !!