There are no apps for mods. They are flash files. So you'll have to use universal flash player to play them. Have no idea about saves, but it is a generally bad idea to transfer saves between mods. The download links are usually at the first message of the mod thread.
Yes, but there are two points here. First, those are exceptions from the rules. Second, they usually understand that their opinion is just their personal and not commonly accepted.
Yes, but we are talking about TiTSverse, so I think that we should assume most lax version of current culture as most hard one of TiTS one. Unless we have a background for the contrary.