Sounds about right. You kinda have to feel through your particular situation. here is my list.

Things I no longer do
1. Wash Dishes that SO and skids make
2. Getting used towels that SD leaves in her room from the weekend
3. Getting dishes left in their rooms
4. Their laundry before they go back to BM
5. Give advice or input in conversation with skids
6. Have conversations with skids.
7. Give input or advice to SO. If asked, I give the most objective and brief answer possible.
8. Correct their inappropriate behavior, burping at the table, rude comments about other people etc.
9. Spend the whole weekend with skids. I do one activity maybe two. Other than that I find something else to do.
10. Put items away that are left on bathroom or kitchen counter
11. Clean for their visit. Whatever cleaning is done is what I would do normally whether they are coming or not.
12. Do favors or parental duties, e.g. Teach SD how to drive, take her to the mall, or entertain her because SO wants to spend time with SS or run his own errands.
13. respond to any negative behavior, eye rolling, huffing, etc.
14. watch or listen to material with skids that makes me uncomfortable because it is age inappropriate.
15. Cook unless SO helps with cooking and clean up.

What I will do
1. If skid asks for medical attention, I will give it
2. If skid talks to me to joke in a friendly manner with me or to ask about me, i will respond in kind.
3. If skid talks to me disrespectfully, they will be told they can cease talking to me until they want to do so respectfully.
4. If skid enters a room i will say hello if I have yet to acknowledge their presence for that day. -- Scratch that. I stopped. They speak to me first now.
5. If skid asks a general question and SO is not around, i will answer. If its for permission or something more involved, I will send them to their dad.
6. If skid invites me to play an activity outside, I will do so. AS long as we are all being respectful of one another.
7. Leave the room if I find any topic of conversation uncomfortable, inappropriate. If I can't leave the room, my headphones go with me (car situations) and those go on.

I retain the right to remove myself from any duties or situations where I feel I am not being respected or appreciated.

Yes, you are disengaged, well done! It is really up to each person to decide how far they are going to take their disengaging. For example, I don't go away on holiday, or even on weekends away with DH and the SDs. I just used to find it not enjoyable at all. SD15 would sabotage everything since the time I first met her at 5 years old. I don't let the SDs have my cell phone no, and I don't ferry them around in the car. I don't go anywhere with them and DH EOW. Whenever possible, I don't even eat with them, as SD15 shows off obnoxiously at the dinnertable and gives me indigestion! If we do all eat together, at the first sign of bad behaviour, I leave the room. It sends a VERY obvious message to DH that I am pissed off.
There is an article you might want to read on the subject http://www.steptogether.org/disengaging.html
PS I see my friend Helena has just posted - I do very similar to her, especially in the what I WILL do list. What I won't do - no9 - I don't do ANY activities with the SDs, at all. Not fun, not worth my effort.

I didn't tell my DH I was going to disengage - it was nearly 9 years ago, and I did not even know then that there was a term for it. I just did it instinctively. I would not advise anyone to announce their intention of disengaging to their partner - it can seem like throwing down the gauntlet, and achieves nothing. Just do it, very, very slowly.