Nice going, CD, regarding the house!! Although I would caution not to into it with the mindset of setting up for sale....which is the opposite of DBing. You would want to claim space as yours to a certain degree to shake up W's view that you are detaching and moving on. Although I would suggest to leave a few of W's stuff so you can convey the message in subtle ways that the porch light is on for her to return.
You want to make W comfortable and safe to turn to you. Yep...the OM and his raggy gang are certainly feeling the pressure from several fronts. And the good part of this is what?!! You need not lift a single finger in that regard. Let the OM hang by his own friggin' rope!
Back to the goals....I would encourage you to have some mini-goals for yourself that will usher a new CD with that much needed swagger! Clothes, shoes/boots, going out with friends/family once a week, finish up a room in the house. I re-did the entire dining room a week before my XW came over (that was when I was DBing actively....guess how long....2 long years!) AND SHE WAS TOTALLY thrown off by it. Couldn't really ignore that big change.
When interacting with W (via text or phone), important to be polite and respectful. She will remember this long after when the OM fades into the background via Twilight Zone of his OWN making!! Do keep up with firewalling your finances...get these done soon.
If W pressures you about the house or divorce, you can use this script:
"W, you know that divorce is not something I want. You can make the contacts yourself."
Put the onus ON THE wayward spouse to initiate these stuff. After all, they think the grass is greener on the other side and let them do the heavy lifting. Oftentimes, from what I've seen of successful DBers, the WAS has a change of heart when the enormity of what they're doing to themselves, LBS, and families hits them dead center between their eyes! And they look at the OM/OW...then they remember all the memories they've build with the LBS and families...it will all come flooding back and they'll eventually take the steps of disengaging from the OW/OM. Especially losers like this 23-year old OM living with HIS family!!!
CD, your years of experience and wisdom will TRUMP this loser. Hang in there dude...I know when I was DBin'g....my PMA would go on a Thunder rollercoaster over and over and OVER! Shoot, I was a card carrying frequent member of the Thunder club!
Although I would caution not to into it with the mindset of setting up for sale....which is the opposite of DBing. You would want to claim space as yours to a certain degree to shake up W's view that you are detaching and moving on. Although I would suggest to leave a few of W's stuff so you can convey the message in subtle ways that the porch light is on for her to return. 
Let the OM hang by his own friggin' rope! 
