I had my baby 3 weeks ago and we had to stay in 2 nights: the list already looks good, I would add:
Tens lady pant/always equivalent are great with a maternity pad added in, you don't have to worry about u your underwear and the extra padding is excellent for a few days after the birth - gives you some cushioning.
Babies can need nappy changing a lot in the first few days and my ward did not have extras so make sure you have enough (and cotton wool pads to clean them with) also so
Flip flops - it's hot in the ward so slippers were not for me, plus you can keep them on in the shower etc.
Towel - I had a shower in the delivery suite after the birth and they supplied one, but nothing in the main ward. I used a microfibre one so it dried really quickly
Normal clothes - I found it good to wash and put on normal clothes (not pjs) during the day, made me feel more like me, that might just be my preference
Dark coloured flannel - really helpful to hold over any sore bits or stitches when you need to use the toilet
Re toiletries for the shower, our antenatal class recommended femfresh shower gel as it would be gentle than normal soap on tender bits
Hope that helps and all goes well