Not really - wheelchair access is not really a priority in Thailand. Very view locations/wats facilitate wheelchairs. You can get into the complex, but not inside temples/buildings

It's free. But you can donate to the temple via the donation boxes.

Hi! You can send them an email (you can find it on internet), or if you are already at Chiang Mai you can go there to the meditation center office and ask them about information. Usually there is plenty of room and you can start the day you want (you can arrive and start straight) and stay as long as you want, usually no more 3-4 weeks, accommodation and meals are provided for a 220 bahts a day fee and you have to wear white clothes (you can buy or rent them there). I recommend you that place for a meditation retreat, for me it was great.

Sorry just saw this - apologies just saw this so answering late. Tuktuk quoted me 100 baht one-way but I asked him to wait an hour for me so paid 300 round trip. But maybe cheaper than average as I used him for other excursions….good luck.

yes this is entirly doable. From Thapae make your way to canal road (the outer of the two ring roads), you can then either cross canal road at the Doi suthep traffic lights, (CM university would then be on your right) contine on for a few 100 metres before takeing one of the left turns and then furtle your way through the lanes for about a kilometer. You should then either pick up a sign or be so close that anyone you ask will be able to dirrect you to the temple. Alternativly turn left at the lights continue on until you see a small lane on the opposite side of the duel carrage way, cross over from which point the temple should be either signposted or again ask in what i am sure is impecable thai. Hope you make it and enjoy your time in CM. then turn left away from chiang mai. after about 500 metres