I don't have 3A hair, but I think KC Come Clean would work for you. For me, it's a very light shampoo (main ingredient is citric acid), and the fact that it's organic and washes out easily doesn't hurt.
I know a lot of 3A's like GDI (Giovanni Direct Leave-in)---for me it's a little light, so I mix it with Trader Joes Nourishing Moisture. Both, however, are light conditioners that should be okay for your hair type.
As for detangling, it can be down either in the shower or after. I prefer doing it in the shower, because it gets me better clumps, but I've done it after. It depends on what (if you use one) product you use to detangle, really. If you're not detangling with a product, and you're finding it difficult and/or painful and/or getting damage, then I recommend getting a moisturizing detangler. Though really, it doesn't need to be moisturizing if you have a leave-in to follow (what do you use?). A lot of people with your hair type co-wash and/or detangle with V05 (it has a lot of slip). You can find that at almost anywhere.
Your wash schedule should purely depend on your needs. No matter what hair type you have, the amount of times per week you need to wash it depends on so many factors, including the weather and the products you use.
Your hair style while you sleep also depends on your personal needs. I use a satin scarf, personally, but most 3A's I know of use either the pineapple or simply a satin/silk pillow case. If your hair isn't long enough to do the pineapple (basically a loose high ponytail of sorts designed to preserve curls overnight), then I recommend a satin/silk scarf or pillow case to sleep on to help with tangles or frizz. If your hair is damp, these techniques should work.
If your hair is dripping wet, then I recommend dabbing the moisture out with a t-shirt before doing the above steps. Whatever you do, don't ever go to bed with a terry cloth towel wrapped around your head. Pretty much a disaster for all hair types.
As far as clips go, most duck bill clips should be able to hold your hair in place for just about any occasion.
Hair Type: 3c, Med-High Density, Low Porosity
CG since '09
Low Poo: KC Come Clean
Condish: AOHR, TN (Avocado), TJ Balancing Moisture
Leave in: GDL, KBB
Curl Lotion/Gel: CHS/CK
Others: CJ Curl Rehab, Jojoba Oil