Digital BW, The Print

Hello, I have some stupid newbie questions that I could not find clear
answers to:

On the Epson R220, I intend to alternate using Epson color (dyebased)
and MIS R2 black and white pigment inks.

1. Will this harm the printer?
2. Is it OK to reinstall partially used cartridges?
3. Do I need to purge with cleaning cartridges when switching ink
types, or is regular head-cleaning enough?
4. Is it better to switch off with pigment color inks rather than dye
inks?

Thanks,
Bob