With making your own powdered sugar you might get some clumps, its best to make small amounts at a time so they don't end up ruined by the time you go to use it. Or you can add things to help with clumping, I can't remember what off the top of my mind. I think a little bit of cornstarch is whats used commercially. If you don't want to actually add anything, you can also store a little baggy of rice (like in a net-ish bag) to absorb any moisture.
I HATE the smell of baby powder. Thats one of the reasons I started making my own, along with needing to save money. I refuse to use talc, and they have talc free baby powder (cornstarch based though and I prefer arrowroot) but its always scented. I don't want a scent due to scent, as well as any added ingredients I may be or become sensitive to.
Apparently some women use HUGE amounts of baby powder inside their pants... I can't remember the reason, a past roommate had told me about it before. And then one day he had to take me to the ER for nonstop vomiting, and this woman who had so much baby powder in her pants you could SEE it puff up when she sat down, sat next to us. I couldn't take the smell with the nausea and vomiting. But she FOLLOWED us around the ER waiting room! We kept moving to get me away from the smell, and they kept sitting down next to us. It may have been because her daughter kept trying to play with my wheelchair. I was laying down across bench seats with my eyes closed so I didn't know until later, but my roommate said her daughter kept touching and trying to push my wheelchair. And everytime he would move my chair a little out of reach from her. Then at one point he told her to stop, and the mother actually gave him a dirty look for it! And started to say something but changed her mind. My wheelchair is custom, it looks NOTHING like a hospital wheelchair and has a large canvas purse hanging off the back for my things. Its not like there could be any confusion of it being personal property.