As for the ball I don't mind using it myself but I'm careful to minimize the risks. It's probably more risky to let him run around in a room without it since there are many other kinds of hazards especially electrical cords. I used it a lot before I trained him to be picked up and carried around but since he was tamed I haven't felt the need for it. My new chin was very tame when I got him and he stays on my (mostly chin-proofed) desk when he runs around.
I do let him run in the bathroom after I've removed everything potentially hazardous from it and give him dust baths in the bathtub which is a good alternative. Also if he chews the baseboards I yell "no!" and slam my hand down or slap him (lightly). It works well to avoid damage. Also I have a covered trash can since my first chin loved to jump in it and make a mess. I have a covered toilet brush as well.
Chinchillas should never be given nuts so I would pick those out immediately. Those can cause liver damage (lipidosis) and fatal diarrhea. My first chin started on Fiesta Max so I mixed it with regular pellets (after removing the fruit and nuts from it) over the course of 5 days without a problem. I did keep the dried fruit and give it as a treat. They should get no more than two pieces a day.
Guinea pigs have very different dietary requirements. I imagine a mix for both is likely good for neither. Don't use a wire hay ball. They are known to kill and maim chins when they get their heads stuck where the wires meet in the center because it gets narrower and they panic and can't free themselves.
I've ordered online from TJ's chinchilla supplies
http://www.tjschinchillasupplies.com/ and had a fast turnaround. I highly recommend them.
I used a wooden feeder I bought at Petsmart for my first chin and removed one of the planks from it to make a larger opening and it works well. Unfortunately my small 300g baby chin was able to fit between the planks and gave me a good scare so I'll wait until he grows to 400g (the size of the other chin) before I give it back. Until then I'll put the hay on the wire floor and it works okay although a lot of hay falls through and gets wasted. I tried putting it on a wooden shelf but he peed on it (strange since he doesn't pee on the shelf unless there's hay on it!) I also tried a large parrot bowl since I use a converted parrot cage that might work for mini bails but is unusable for regular loose hay. I do have a Ware Products metal J-feeder that I use for pellets. It has a wire mesh floor that lets the crumbles fall through and has worked nicely for me. I'm thinking about ordering a new wooden hay feeder from TJ's that's made for chins.
As far as naming I called mine by his chinchilla number (B48) for weeks before I named him. I named him K'ulu, supposedly the Mayan word for Raccoon, in honor of the infamous end of the world in 2012 which happened the same week I got him and his late night ruckuses. I wanted to name him Bix (Bix is pronounced beesh) ak'aaba ("What is your name?") but no one else could pronounce it so I found a simpler word.
The 5lb bag of Oxbow I purchased at Petsmart was about $15.00 so that sounds pretty good to me.