you right I rechecked the website of the Thai embassy in Rome and it has changed from when I applied in june, it now requires 2 tickets. So the OP should comply.
it is not required to show more than one ticket in and out of Thailand only the first trip is required, it’s a strange request from the e-visa team, the requirement is clear, he should just reach out and talk to them.
that is absolutely incorrect, I applied for the same just showing one return booking and the visa was issued without any further request more over the official requirement states that booking should be presented for the first trip at least. The OP might have a visa history in thailand or did not present enough documentation. He should enquire directly with the embassy in Rome providing at least one return booking and stating that the for the second trip the plan is not yet finalized.
It is a breach of contract, as one of the conditions of all rental contracts is that you should be able to enjoy the property peacefully, this is not the case, therefore you just need to find a friendly lawyer to cite this in a letter and you will get your deposit back, if you used and agent seek his help, he made his commission so if he is willing to give it back (that is one of the reasons he doesn’t want to give the deposit back) and you rent again from him he might help.
that can only be if you are in overstay or if you committed a crime, like in any other country, not to be allowed on a domestic flight unless you have criminal charges doesn’t happen