Are you simply trying to mess with us about the selfie thing? Since I usually try to stick with Beijing, HK, and Shanghai, I can sort of understand why you might not want to head west, but if you have time, doing so definitely helps round out your trip.

No hands on photos.

• Make panda food, clean the enclosures, and help feed the pandas

Definitely not messing with you. The panda picture was going to be a highlight of the trip and that appears to be out the door so I'm quite bummed about that.

Pandas alone should not be the reason to go to Chengdu (although it is obviously a great perk). Chengdu is one of my favorite cities in China. Assuming you haven't been to Sichuan, the food is amazing (and yes, hot-pot is that much better there). The Giant Buddha is amazing (but check on that, because I think they are doing massive renovations on it right now. Would not be fun to get all the way there and have it covered in scaffolding). And Dujiangyan is well worth a day trip. Chengdu is such a nice, green, easy-going city, especially compared to other cities in China.
The Pandas are great, but to actually get a selfie is very disappointing. It is very expensive, even by US standards, and you will quite literally get 30 seconds to hold it and snap one photo, not to mention you'll wait in an extremely long line for the pleasure.
I had a much better experience at the Chengdu Panda Base where, yes, it is set up like a zoo. However, go in off-peak and it wasn't crowded at all and you can still get very, very close to the pandas (and red pandas, which I don't believe the other locations have).

I hit the panda base first thing in the morning right as it opened. Was nice and quiet and I got to see the pandas coming out of their cages and eating. The problem with going later is that not only does it get crowded but the pandas are less active because their bellies are full.

The repair of Leshan Buddha has been completed. It is now reopened.
Chengdu Panda Base,This Spring Festival, more than 20,000 people come to this park every day.So I suggest you go to Wolong Panda Base. There are only 100 tourists here every day.