Here's what we do:
- We don't have cable, it's DVDs only. The remote is kept out of reach and the buttons are awkward, so DD can't turn the TV on by herself.
- Limit for screen time is 1/2 hour per day, DD has choice of TV, computer (sesamestreet.com), or games on DH's iPhone. DD is allowed to play with the computer outside of that time to "type" and play with MS Paint. She will do this for a couple of hours once or twice a week. I have no problem with this and haven't set limits.
- TV time is after quiet time or nap, which is after lunch. If there are any issues with quiet time, no TV. I hate that I am so structured but it just works so well. Quiet time is alone time in her room, which helped her develop the ability to play alone. We also used to fight about naps, and since I no longer insist on a nap, she will just take one if she's tired.
- We set the kitchen timer and DD is the one responsible for turning off TV/computer when she hears it. We will allow to the end of the song or scene. If she doesn't turn it off right away we come and sit with her and ask her if she wants us to do it. Usually she is reasonable about it.
- Meltdowns: if there is a problem with turning it off, no screen time the next day. She will generally get one warning for this. I have enforced this, but haven't had to for a long time.
DH and I do not watch TV or play video games when she is awake, unless she is playing with the computer, and then we shut it off when the time is up.
We have talked to her about how it is hard to stop watching TV, and TV is lots of fun but you need to do other things too besides staring at a screen all day. Downside to this: gets thrown back in your face if you wanna check out MDC with your morning coffee
YES, it is reasonable to expect your DS to play by himself for short periods...eventually. He'll probably need to work up to this. You don't necessarily need to play with him if you don't want to - you can include him in whatever you're doing, set up activities for him, or do an outing or playdate.
I think you're right to worry about your DS's reaction to the change. Can you explain your problem with TV to him and enlist him in helping you set the rules and routines? Have him come up with a list of things to do instead of TV, then work together to set them up so he can do them on his own. When I first started SAH with DD after working for 2 years, we planned our day every morning and crossed things off. It really helped both of us get into a good routine.