Hope that you are well, I looked at your link today on BBC Wales, your positive attitude puts a smile on my face. As Liz and Kris advised PEK is probably one of the better places for disability access, I lived there for a year and saw lots of people getting around with disiabilities. There are taxi's everywhere you look in PEK and so you will not be short of them which I would say is the most easiest transport option especially for me too and 90% of them are more than willing to help, though its not the same when my fiance had an operation a few months ago he had trouble walking and the taxi's were fantastic, so helpful. You will have a great holiday and I'm sure Liz or toonssia will give you some more advice.
When I went to Spain 3 years ago, we hired a wheelchair through this company for a friend who is also active, but to be on the safe side we hired a wheelchair – the company is very good.
We’ve got some relatives in Tunisia with problems with their feet, however the taxis and louage are always helpful and mindful of disability and I can’t envisage any challenges for you. Best of luck and have a fab holiday. Love PEK.
hope you'll enjoy your trip but am 99% sure you will, Tunisian transport aren't the best for disable person but people are very very helpful you wont get any problem going around but you might sometimes need help (that you'll find).
Wish you all the best have fun!