The reason behind being unable to redo Hecate fight+Intervention thing (yes, those are the only things you are forced to skip) is because of your global save. This also happens with both Titania and Giant Sphinx fight on EX3. If you play on a clear global save it should trigger them normally.
EX4 is translated but you need to go to the translators page to get the patch.
Yes, but you need to download another Patch and update, the version that has translation is 8.07
There's a trial version that you can get for free on DLsite but it's currently not translated. I'd recommend waiting an update and a translation before getting it, managed to reach the end of the content a few months ago but it took a lot of trial and error to complete. I also found that it was pretty laggy during H-scenes but that could be due to the potato I use to run it (although Shrift 1 runs fine for me).
Loss scenes are unlocked when you fully watch them at least once (same as base game and rest of EX scenarios). In other words, you have to lose the combat/get caught during a chase sequence. Sometimes you also need to perform something to trigger it.
I got a set of EX4 loss scenes without losing to anyone upon finishing it, not sure if it's something the developer implemented or part of the TL patch, yet no sign of the bed scene.
