The female character in the first four preview images is not a love interest as of now (meaning you can't pursue her route since there currently isn't one)
Voyeurism is not planned for this game. Swinging though might be in future versions (Still being planned/written). Now, if you see NTR as you being "cuckolded" then no it is not planned, however, if you see it as you're doing the "cuckolding" then yes it might be present in future versions. "Why is he saying "might" a lot?" you may ask. Because I am still putting it all together in my head, writing-wise. Still considering all the routes and how the different characters might be affected by the "NTR" or "Swinging" tags.
That scene is skippable. The game is not "pov", meaning it isn't solely focused on the mc but focused on all the characters in the game. I wanted to be able to show all the present characters' personalities. How they think, what they like to wear, their love interests, etc.
The female from the first four preview images is the guy's wife.
That's okay. I love it when I get questions like this, so thank you for taking the time of your day to ask this question.
I hope I answered your questions and if you have any more just reply to the thread or pm me (whatever you're comfortable with) and I'll be sure to try and answer them.